examples/qsvdec: do not set the deprecated field refcounted_frames

It is used by the deprecated API avcodec_decode_video2 and ignored by the
new decode APIs (avcodec_send_packet/avcodec_receive_frame).
Signed-off-by: Zhong Li <zhong.li@intel.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

doc/examples/qsvdec.c

@@ -210,7 +210,6 @@ int main(int argc, char **argv)
                video_st->codecpar->extradata_size);
         decoder_ctx->extradata_size = video_st->codecpar->extradata_size;
     }
-    decoder_ctx->refcounted_frames = 1;
 
     decoder_ctx->opaque      = &decode;
     decoder_ctx->get_format  = get_format;