avcodec/dxtory: Fix input size check in dxtory_decode_v1_420()

Fixes out of array read
Fixes: c50c4aa6cefda71b19a31ea12302980c/asan_heap-oob_12be5fd_7011_33ebd015a74976215934add72b9c8352.avi

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/dxtory.c

@@ -108,7 +108,7 @@ static int dxtory_decode_v1_420(AVCodecContext *avctx, AVFrame *pic,
     uint8_t *Y1, *Y2, *U, *V;
     int ret;
 
-    if (src_size < avctx->width * avctx->height * 3LL / 2) {
+    if (src_size < FFALIGN(avctx->width, 2) * FFALIGN(avctx->height, 2) * 3LL / 2) {
         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
         return AVERROR_INVALIDDATA;
     }