Fix typo in gralloc.h

Change-Id: I8d989b21e10e19ae4124188f02ef84eeabdb4654
diff --git a/include/hardware/gralloc.h b/include/hardware/gralloc.h
index f8beb5e..2dbd1fa 100644
--- a/include/hardware/gralloc.h
+++ b/include/hardware/gralloc.h
@@ -258,4 +258,4 @@
 
 __END_DECLS
 
-#endif  // ANDROID_ALLOC_INTERFACE_H
+#endif  // ANDROID_GRALLOC_INTERFACE_H