av_samples_alloc_array_and_samples: Fix sizeof type.

Fixes CID1005317
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavutil/samplefmt.c

@@ -212,7 +212,7 @@ int av_samples_alloc_array_and_samples(uint8_t ***audio_data, int *linesize, int
 {
     int ret, nb_planes = av_sample_fmt_is_planar(sample_fmt) ? nb_channels : 1;
 
-    *audio_data = av_calloc(nb_planes, sizeof(*audio_data));
+    *audio_data = av_calloc(nb_planes, sizeof(**audio_data));
     if (!*audio_data)
         return AVERROR(ENOMEM);
     ret = av_samples_alloc(*audio_data, linesize, nb_channels,