Fix some warnings.

--
MOS_MIGRATED_REVID=102332437
diff --git a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
index ddbda14..59fcbb5 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/RuleClass.java
@@ -191,7 +191,7 @@
         @Override
         public String getCategory() {
           return "core";
-        };
+        }
   };
 
   /**