Normalize on 'charsetName' as a parameter name since this is the named

used in the JRE for Charset.forName(String).

- Use 'charset' instead of 'encoding' Charset parameter names.
- Fix 1 checkstyle issue.

Author: garydgregory

src/main/java/org/apache/commons/io/Charsets.java

@@ -97,14 +97,14 @@ public static Charset toCharset(final Charset charset) {
     /**
      * Returns a Charset for the named charset. If the name is null, return the default Charset.
      *
-     * @param charset
+     * @param charsetName
      *            The name of the requested charset, may be null.
      * @return a Charset for the named charset
      * @throws java.nio.charset.UnsupportedCharsetException
      *             If the named charset is unavailable
      */
-    public static Charset toCharset(final String charset) {
-        return charset == null ? Charset.defaultCharset() : Charset.forName(charset);
+    public static Charset toCharset(final String charsetName) {
+        return charsetName == null ? Charset.defaultCharset() : Charset.forName(charsetName);
     }
 
     /**