iris: Drop buffer support in resource_from_handle

The callers don't seem to pass targets of PIPE_BUFFER. Stop nesting an
if-else block by dropping support for this target.

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6311>
1 file changed