avcodec/utils: Check all data[] pointers in video_get_buffer() not just the first

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/utils.c

@@ -656,8 +656,8 @@ static int video_get_buffer(AVCodecContext *s, AVFrame *pic)
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
     int i;
 
-    if (pic->data[0]) {
+    if (pic->data[0] || pic->data[1] || pic->data[2] || pic->data[3]) {
-        av_log(s, AV_LOG_ERROR, "pic->data[0]!=NULL in avcodec_default_get_buffer\n");
+        av_log(s, AV_LOG_ERROR, "pic->data[*]!=NULL in avcodec_default_get_buffer\n");
         return -1;
     }