avcodec/mpegvideo: Remove pointless check

Possible since 315c956cbd.

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

libavcodec/mpegvideo.c

@@ -789,9 +789,6 @@ void ff_mpv_common_end(MpegEncContext *s)
     av_freep(&s->bitstream_buffer);
     s->allocated_bitstream_buffer_size = 0;
 
-    if (!s->avctx)
-        return;
-
     if (s->picture) {
         for (int i = 0; i < MAX_PICTURE_COUNT; i++)
             ff_mpv_picture_free(&s->picture[i]);