Use a consistent style for the terminating endif for include guards

include/dav1d/common.h

@@ -67,4 +67,4 @@ typedef struct Dav1dDataProps {
     struct Dav1dUserData user_data; ///< user-configurable data, default NULL members
 } Dav1dDataProps;
 
-#endif // __DAV1D_COMMON_H__
+#endif /* __DAV1D_COMMON_H__ */

src/thread.h

@@ -108,4 +108,4 @@ static inline int pthread_cond_broadcast(pthread_cond_t *const cond) {
 
 #endif
 
-#endif // __DAV1D_THREAD_H__
+#endif /* __DAV1D_THREAD_H__ */