avfilter/avfiltergraph: fix check for negative return

Before this commit if allocation would fail in ff_add_channel_layout()
function, function would return negative error code and this would
cause wrong format pick up later. If allocation would not fail return
code would be 0 and then format negotiation would simply fail as code
would break from the loop but with wrong return code.

Error was introduced in 6aaac24d72a7da commit.

Fixes #6638

0 files changed, 0 insertions, 0 deletions