Fix uninitialized variable warning(error).

Change-Id: I10815b033199758976950b28af7cc412f093a7f5
diff --git a/vm/compiler/codegen/arm/Assemble.c b/vm/compiler/codegen/arm/Assemble.c
index 4f54f1e..cf5c41f 100644
--- a/vm/compiler/codegen/arm/Assemble.c
+++ b/vm/compiler/codegen/arm/Assemble.c
@@ -1616,6 +1616,7 @@
     newCell.branch = assembleChainingBranch(branchOffset, true);
     newCell.clazz = clazz;
     newCell.method = method;
+    newCell.stagedClazz = NULL;
 
     /*
      * Enter the work order to the queue and the chaining cell will be patched