Simplify copying arrays.

Author: Gary Gregory

src/main/java/org/apache/commons/io/filefilter/MagicNumberFileFilter.java

@@ -172,8 +172,7 @@ public MagicNumberFileFilter(final byte[] magicNumbers, final long offset) {
             throw new IllegalArgumentException("The offset cannot be negative");
         }
 
-        this.magicNumbers = IOUtils.byteArray(magicNumbers.length);
-        System.arraycopy(magicNumbers, 0, this.magicNumbers, 0, magicNumbers.length);
+        this.magicNumbers = magicNumbers.clone();
         this.byteOffset = offset;
     }