gallium/cso: avoid unnecessary null dereference

The label `out:` calls `destroy()` which dereferences `ctx`.
This is unnecessary as there is nothing to destroy.
Immediately return instead.

CovID: 1258255
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
1 file changed