Fix some Javadoc issues

Author: garydgregory

src/changes/changes.xml

@@ -49,6 +49,7 @@ The <action> type attribute can be add,update,fix,remove.
     <release version="2.17.1" date="YYYY-MM-DD" description="Version 2.17.1: Java 8 is required.">
       <!-- FIX -->
       <action dev="ggregory" type="fix"                due-to="Gary Gregory">Clean ups in unit tests.</action>
+      <action dev="ggregory" type="fix"                due-to="Gary Gregory">Fix some Javadoc issues.</action>      
       <!-- ADD -->
       <action dev="ggregory" type="add"                due-to="Gary Gregory">Add @FunctionalInterface to ClassNameMatcher.</action>
       <action dev="ggregory" type="add"                due-to="Gary Gregory">Add ValidatingObjectInputStream.Builder and ValidatingObjectInputStream.builder().</action>

src/main/java/org/apache/commons/io/build/AbstractOrigin.java

@@ -322,7 +322,7 @@ public Path getPath() {
     }
 
     /**
-     * An {@link Reader} origin.
+     * A {@link Reader} origin.
      * <p>
      * This origin cannot provide other aspects.
      * </p>
@@ -423,7 +423,7 @@ public Path getPath() {
     }
 
     /**
-     * An {@link Writer} origin.
+     * A {@link Writer} origin.
      * <p>
      * This origin cannot provide other aspects.
      * </p>