vf_sab: use av_malloc_array()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/vf_sab.c

@@ -180,7 +180,7 @@ static int open_filter_param(FilterParam *f, int width, int height, unsigned int
     vec = sws_getGaussianVec(f->radius, f->quality);
     f->dist_width    = vec->length;
     f->dist_linesize = FFALIGN(vec->length, 8);
-    f->dist_coeff    = av_malloc(f->dist_width * f->dist_linesize * sizeof(*f->dist_coeff));
+    f->dist_coeff    = av_malloc_array(f->dist_width, f->dist_linesize * sizeof(*f->dist_coeff));
     if (!f->dist_coeff) {
         sws_freeVec(vec);
         return AVERROR(ENOMEM);