Fix Checkstyle build failure

Author: garydgregory

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

@@ -135,7 +135,7 @@ public long skip(final long n) throws IOException {
         if (n <= 0) {
             return super.skip(n);
         }
-        int remaining = maxCharsFromTargetReader - charsRead;
+        final int remaining = maxCharsFromTargetReader - charsRead;
         if (remaining <= 0) {
             return 0;
         }