smush: read subversion for version==1 too.

This avoids a gcc warning, otherwise it should have no effect.
its a bit more consistent too
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/smush.c

@@ -79,7 +79,7 @@ static int smush_read_header(AVFormatContext *ctx)
             return AVERROR_INVALIDDATA;
 
         smush->version = 1;
-        avio_skip(pb, 2); // skip version
+        subversion     = avio_rl16(pb);
         nframes = avio_rl32(pb);
         avio_skip(pb, 2); // skip pad
         width  = avio_rl16(pb);