dvbsubdec: Fix "set but not used" warning

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/dvbsubdec.c

@@ -1031,7 +1031,7 @@ static void dvbsub_parse_region_segment(AVCodecContext *avctx,
 
     const uint8_t *buf_end = buf + buf_size;
     int region_id, object_id;
-    int version;
+    int av_unused version;
     DVBSubRegion *region;
     DVBSubObject *object;
     DVBSubObjectDisplay *display;