Add @SuppressWarnings.

Author: garydgregory

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

@@ -171,11 +171,13 @@ public boolean markSupported() {
         return true;
     }
 
+    @SuppressWarnings("sync-override")
     @Override
     public void mark(final int readlimit) {
         this.markedOffset = this.offset;
     }
 
+    @SuppressWarnings("sync-override")
     @Override
     public void reset() {
         this.offset = this.markedOffset;