avcodec/dump_extradata_bsf: Remove unnecessary header

Since 33d18982fa (the commit that
introduced the new bsf API) allocating an enlarged buffer in case
extradata needs to be added to a packet is done via av_new_packet(),
so that libavutil/mem.h is no longer needed.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavcodec/dump_extradata_bsf.c

@@ -24,7 +24,6 @@
 #include "bsf.h"
 
 #include "libavutil/log.h"
-#include "libavutil/mem.h"
 #include "libavutil/opt.h"
 
 enum DumpFreq {