Fix a lint error and update a test after the phi fix.

Change-Id: I6e9ab2a8300c2493a8d3e93ab4ced3d7c9552fc5
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index a4c8ce5..aae65ec 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -339,7 +339,7 @@
   }
 
   void SwapPredecessors() {
-    DCHECK(predecessors_.Size() == 2);
+    DCHECK_EQ(predecessors_.Size(), 2u);
     HBasicBlock* temp = predecessors_.Get(0);
     predecessors_.Put(0, predecessors_.Get(1));
     predecessors_.Put(1, temp);