avcodec/asvenc: Remove unnecessary emms_c()

PixblockDSP does not use MMX functions any more since
92b5800277 and FDCTDSP
since d402ec6be9.
BswapDSP never used MMX, so that the emms_c() here
is unnecessary.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/asvenc.c

@@ -300,7 +300,6 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
             encode_mb(a, a->block);
         }
     }
-    emms_c();
 
     if (avctx->codec_id == AV_CODEC_ID_ASV1)
         flush_put_bits(&a->pb);