zink: do not try to dereference null-key
We can't do any of this logic if key is NULL, because that means we'll
dereference memory close to a NULL-pointer.
While we're at it, add some asserts to the zink_fs_key and zink_vs_key
functions who would otherwise be responsible for giving us invalid
non-null pointers out of null-pointers.
CID: 1475973, 1475983
Reviewed-By: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12559>
2 files changed
