Replace magic 0 with enum in surfacecontrol

Test: m
Fixes: nothing
Change-Id: Iab9348dcf57bfb72069655ec9fc7f443d30f3e1b
diff --git a/libs/gui/SurfaceControl.cpp b/libs/gui/SurfaceControl.cpp
index 19ad31b..3a6dfda 100644
--- a/libs/gui/SurfaceControl.cpp
+++ b/libs/gui/SurfaceControl.cpp
@@ -102,14 +102,14 @@
 
 status_t SurfaceControl::clearLayerFrameStats() const {
     status_t err = validate();
-    if (err < 0) return err;
+    if (err != NO_ERROR) return err;
     const sp<SurfaceComposerClient>& client(mClient);
     return client->clearLayerFrameStats(mHandle);
 }
 
 status_t SurfaceControl::getLayerFrameStats(FrameStats* outStats) const {
     status_t err = validate();
-    if (err < 0) return err;
+    if (err != NO_ERROR) return err;
     const sp<SurfaceComposerClient>& client(mClient);
     return client->getLayerFrameStats(mHandle, outStats);
 }