Fix SpotBugs issues in UnixLineEndingInputStream

- [ERROR] Medium: Shared primitive variable "atSlashLf" in one thread
may not yield the value of the most recent write from another thread
[org.apache.commons.io.input.UnixLineEndingInputStream] At
UnixLineEndingInputStream.java:[line 75]
AT_STALE_THREAD_WRITE_OF_PRIMITIVE
- [ERROR] Medium: Shared primitive variable "atEos" in one thread may
not yield the value of the most recent write from another thread
[org.apache.commons.io.input.UnixLineEndingInputStream] At
UnixLineEndingInputStream.java:[line 120]
AT_STALE_THREAD_WRITE_OF_PRIMITIVE
- [ERROR] Medium: Shared primitive variable "atSlashCr" in one thread
may not yield the value of the most recent write from another thread
[org.apache.commons.io.input.UnixLineEndingInputStream] At
UnixLineEndingInputStream.java:[line 124]
AT_STALE_THREAD_WRITE_OF_PRIMITIVE
- [ERROR] Medium: Shared primitive variable "atSlashLf" in one thread
may not yield the value of the most recent write from another thread
[org.apache.commons.io.input.UnixLineEndingInputStream] At
UnixLineEndingInputStream.java:[line 125]
AT_STALE_THREAD_WRITE_OF_PRIMITIVE

Author: garydgregory

src/changes/changes.xml

@@ -60,6 +60,10 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "atSlashCr" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.WindowsLineEndingInputStream, org.apache.commons.io.input.WindowsLineEndingInputStream] At WindowsLineEndingInputStream.java:[line 77]Another occurrence at WindowsLineEndingInputStream.java:[line 81] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "atSlashCr" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.WindowsLineEndingInputStream] At WindowsLineEndingInputStream.java:[line 112] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "atSlashLf" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.WindowsLineEndingInputStream] At WindowsLineEndingInputStream.java:[line 113] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "atSlashLf" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.UnixLineEndingInputStream] At UnixLineEndingInputStream.java:[line 75] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "atEos" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.UnixLineEndingInputStream] At UnixLineEndingInputStream.java:[line 120] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "atSlashCr" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.UnixLineEndingInputStream] At UnixLineEndingInputStream.java:[line 124] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix SpotBugs [ERROR] Medium: Shared primitive variable "atSlashLf" in one thread may not yield the value of the most recent write from another thread [org.apache.commons.io.input.UnixLineEndingInputStream] At UnixLineEndingInputStream.java:[line 125] AT_STALE_THREAD_WRITE_OF_PRIMITIVE.</action>
       <!-- ADD -->
       <action dev="ggregory" type="add" issue="IO-875" due-to="Pierre Baumard, Gary Gregory">Add and use org.apache.commons.io.file.CountingPathVisitor.accept(Path, BasicFileAttributes) #743.</action> 
       <!-- UPDATE -->

src/main/java/org/apache/commons/io/input/UnixLineEndingInputStream.java

@@ -90,7 +90,7 @@ public synchronized void mark(final int readLimit) {
      * {@inheritDoc}
      */
     @Override
-    public int read() throws IOException {
+    public synchronized int read() throws IOException {
         final boolean previousWasSlashR = atSlashCr;
         if (atEos) {
             return handleEos(previousWasSlashR);