jpeg2000dec: return error for invalid cdxy values

Fixes division by 0

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/jpeg2000dec.c

@@ -194,6 +194,8 @@ static int get_siz(Jpeg2000DecoderContext *s)
         s->cdy[i]    = bytestream2_get_byteu(&s->g);
         if (s->cdx[i] != 1 || s->cdy[i] != 1) {
             av_log(s->avctx, AV_LOG_ERROR, "unsupported/ CDxy values %d %d for component %d\n", s->cdx[i], s->cdy[i], i);
+            if (!s->cdx[i] || !s->cdy[i])
+                return AVERROR_INVALIDDATA;
         }
     }