Remove trailing whitespace

Use final

src/main/java/org/apache/commons/csv/ExtendedBufferedReader.java

@@ -57,7 +57,7 @@ final class ExtendedBufferedReader extends UnsynchronizedBufferedReader {
     }
 
     @Override
-    public void mark(int readAheadLimit) throws IOException {
+    public void mark(final int readAheadLimit) throws IOException {
         lineNumberMark = lineNumber;
         lastCharMark = lastChar;
         positionMark = position;