folly/test/SynchronizedTestLib-inl.h: avoid shadowing warnings

Summary: Fix warnings exposed by the upstream-proposed -Wshadow-compatible-local option.

Reviewed By: igorsugak

Differential Revision: D4041931

fbshipit-source-id: fcddbc8636c16124a9711c4491a08cc7db76a224

folly/test/SynchronizedTestLib-inl.h

@@ -468,15 +468,15 @@ void testDeprecated() {
     EXPECT_EQ(10, obj.back());
     EXPECT_EQ(1000, obj2->size());
 
-    UNSYNCHRONIZED(obj) {
-      EXPECT_EQ(1001, obj->size());
+    UNSYNCHRONIZED(o) {
+      EXPECT_EQ(1001, o->size());
     }
   }
 
   SYNCHRONIZED_CONST (obj) {
     EXPECT_EQ(1001, obj.size());
-    UNSYNCHRONIZED(obj) {
-      EXPECT_EQ(1001, obj->size());
+    UNSYNCHRONIZED(o) {
+      EXPECT_EQ(1001, o->size());
     }
   }