avformat/mxfenc: resurrects the error print

Fixes: CID1524681 Logically dead code

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit a469e48b6d)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/mxfenc.c

@@ -2494,9 +2494,6 @@ static int mxf_parse_ffv1_frame(AVFormatContext *s, AVStream *st, AVPacket *pkt)
         ff_build_rac_states(&c, 0.05 * (1LL << 32), 256 - 8);
         v = get_ffv1_unsigned_symbol(&c, state);
         av_assert0(v >= 2);
-        if (v > 4) {
-            return 0;
-        }
         if (v > 4) {
             av_log(s, AV_LOG_ERROR, "unsupported ffv1 version %d\n", v);
             return 0;