lavc: do not force the emu edge flag

The default get_buffer2() implementation (and possibly some
user ones) does not allocate edges when this flag is set, which may
expose bugs in some decoders. Until the 10 release is out, it is safer
to remove this part.

libavcodec/utils.c

@@ -1091,11 +1091,6 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
             ret = AVERROR(EINVAL);
             goto free_and_end;
         }
-
-#if FF_API_EMU_EDGE
-        /* force the emu edge flag on, since it's now always active */
-        avctx->flags |= CODEC_FLAG_EMU_EDGE;
-#endif
     }
 end:
     entangled_thread_counter--;