don't cast const away

Originally committed as revision 11801 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h263_parser.c

@@ -77,7 +77,7 @@ static int h263_parse(AVCodecParserContext *s,
         return buf_size;
     }
 
-    *poutbuf = (uint8_t *)buf;
+    *poutbuf = buf;
     *poutbuf_size = buf_size;
     return next;
 }