ffprobe: make function replacement macros behave correctly

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/ffprobe.c b/ffprobe.c
index dd4358d..8129bce 100644 (file)
--- a/ffprobe.c
+++ b/ffprobe.c
@@ -57,11 +57,11 @@
 #  ifdef pthread_mutex_lock
 #    undef pthread_mutex_lock
 #  endif
-#  define pthread_mutex_lock(a)
+#  define pthread_mutex_lock(a) do{}while(0)
 #  ifdef pthread_mutex_unlock
 #    undef pthread_mutex_unlock
 #  endif
-#  define pthread_mutex_unlock(a)
+#  define pthread_mutex_unlock(a) do{}while(0)
 #endif
 
 typedef struct InputStream {