Fix the issue that weak annotation didn't work

src/butil/third_party/dynamic_annotations/dynamic_annotations.c

@@ -255,7 +255,7 @@ static int GetRunningOnValgrind(void) {
 }
 
 /* See the comments in dynamic_annotations.h */
-int DYNAMIC_ANNOTATIONS_ATTRIBUTE_WEAK RunningOnValgrind(void) {
+int __attribute__((weak)) RunningOnValgrind(void) {
   static volatile int running_on_valgrind = -1;
   /* C doesn't have thread-safe initialization of statics, and we
      don't want to depend on pthread_once here, so hack it. */