avcodec/dca_core_bsf: Remove unnecessary header

This bsf never needed libavutil/mem.h.
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavcodec/dca_core_bsf.c

@@ -22,7 +22,6 @@
 #include "bsf.h"
 #include "bytestream.h"
 #include "dca_syncwords.h"
-#include "libavutil/mem.h"
 
 static int dca_core_filter(AVBSFContext *ctx, AVPacket *pkt)
 {