Use #equals() to check equality between ExitCode instances.

--
MOS_MIGRATED_REVID=139180153
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/BuildResult.java b/src/main/java/com/google/devtools/build/lib/buildtool/BuildResult.java
index 42bf33d..8bbc62c 100644
--- a/src/main/java/com/google/devtools/build/lib/buildtool/BuildResult.java
+++ b/src/main/java/com/google/devtools/build/lib/buildtool/BuildResult.java
@@ -82,7 +82,7 @@
    * True iff the build request has been successfully completed.
    */
   public boolean getSuccess() {
-    return exitCondition == ExitCode.SUCCESS;
+    return exitCondition.equals(ExitCode.SUCCESS);
   }
 
   /**