h264: notice memory allocation failure

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit bac3ab13ea)

Signed-off-by: Anton Khirnov <anton@khirnov.net>
(cherry picked from commit 59a22afa0b)

Conflicts:

	libavcodec/h264.c

Signed-off-by: Reinhard Tartler <siretart@tauware.de>

libavcodec/h264.c

@@ -1840,7 +1840,10 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
         h->prev_interlaced_frame = 1;
 
         init_scan_tables(h);
-        ff_h264_alloc_tables(h);
+        if (ff_h264_alloc_tables(h) < 0) {
+            av_log(h->s.avctx, AV_LOG_ERROR, "Could not allocate memory for h264\n");
+            return AVERROR(ENOMEM);
+        }
 
         for(i = 1; i < s->avctx->thread_count; i++) {
             H264Context *c;