fixed a typo in a javadoc comment.

git-svn-id: http://anonsvn.jboss.org/repos/javassist/trunk@609 30ef5769-5b8d-40dd-aea6-55b5d6557bb3

src/main/javassist/bytecode/analysis/ControlFlow.java

@@ -271,7 +271,6 @@ public class ControlFlow {
 
         /**
          * Returns the length of this block.
-         * @return
          */
         public int length() { return length; }