avcodec/bink: use av_mallocz for data

Fixes use of uninitialized memory
Fixes msan_uninit-mem_7fe8a5fd759d_2838_SPECTRE.BIK
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/bink.c

@@ -185,7 +185,7 @@ static av_cold int init_bundles(BinkContext *c)
     blocks = bw * bh;
 
     for (i = 0; i < BINKB_NB_SRC; i++) {
-        c->bundle[i].data = av_malloc(blocks * 64);
+        c->bundle[i].data = av_mallocz(blocks * 64);
         if (!c->bundle[i].data)
             return AVERROR(ENOMEM);
         c->bundle[i].data_end = c->bundle[i].data + blocks * 64;