libavutil: remove unused av_abort() macro

Signed-off-by: Mans Rullgard <mans@mansr.com>

libavutil/internal.h

@@ -56,10 +56,6 @@ struct AVDictionary {
 #    define INT_BIT (CHAR_BIT * sizeof(int))
 #endif
 
-/* debug stuff */
-
-#define av_abort()      do { av_log(NULL, AV_LOG_ERROR, "Abort at %s:%d\n", __FILE__, __LINE__); abort(); } while (0)
-
 /* avoid usage of dangerous/inappropriate system functions */
 #undef  malloc
 #define malloc please_use_av_malloc