Merge commit '964fef3f3ced60e67831549df223bc177e1537c9' into release/2.2

* commit '964fef3f3ced60e67831549df223bc177e1537c9':
  h264: Make sure reinit failures mark the context as not initialized

See: e8714f6f93
Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/h264.c

@@ -3670,6 +3670,7 @@ static int decode_slice_header(H264Context *h, H264Context *h0)
          h->height != h->avctx->coded_height  ||
          must_reinit ||
          needs_reinit)) {
+        h->context_initialized = 0;
         if (h != h0) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "changing width %d -> %d / height %d -> %d on "