8303084: G1 Heap region liveness verification has inverted return value

Reviewed-by: ayang

src/hotspot/share/gc/g1/heapRegion.cpp

@@ -535,10 +535,10 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {
       }
       log.error("----------");
       _num_failures++;
-      return true;
-    }
       return false;
     }
+    return true;
+  }
 
   template <class T>
   void verify_remset(T* p, oop obj) {