ffmpeg: Add a missing line break when requesting a sample.

ffmpeg.c

@@ -2258,7 +2258,7 @@ static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output, int eo
                    "video_delay is larger in decoder than demuxer %d > %d.\n"
                    "If you want to help, upload a sample "
                    "of this file to ftp://upload.ffmpeg.org/incoming/ "
-                   "and contact the ffmpeg-devel mailing list. (ffmpeg-devel@ffmpeg.org)",
+                   "and contact the ffmpeg-devel mailing list. (ffmpeg-devel@ffmpeg.org)\n",
                    ist->dec_ctx->has_b_frames,
                    ist->st->codecpar->video_delay);
     }