OGG: Add padding at end of Vorbis headers

Patch by Siarhei Siamashka <siarhei.siamashka gmail com>

Originally committed as revision 14249 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/oggparsevorbis.c

@@ -146,7 +146,7 @@ fixup_vorbis_headers(AVFormatContext * as, oggvorbis_private_t *priv,
         memcpy(&ptr[offset], priv->packet[i], priv->len[i]);
         offset += priv->len[i];
     }
-    *buf = av_realloc(*buf, offset);
+    *buf = av_realloc(*buf, offset + FF_INPUT_BUFFER_PADDING_SIZE);
     return offset;
 }