drm/xe/oa: Check managed mutex initialization errors

drm/xe/oa: Check managed mutex initialization errors

drmm_mutex_init() can fail while registering its managed cleanup action.
On failure, the reset path destroys the mutex, so continuing OA setup
leaves an unusable lock that later paths may acquire.

Return the error from per-GT OA initialization and abort device-wide OA
initialization if the metrics lock cannot be initialized.

Fixes: a9f905ae7b6f ("drm/xe/oa/uapi: Initialize OA units")
Fixes: cdf02fe1a94a ("drm/xe/oa/uapi: Add/remove OA config perf ops")
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Link: https://patch.msgid.link/20260713083053.321091-1-lilinmao@kylinos.cn
(cherry picked from commit 360b293de27bfdd0d07047f8efd5ba8e91fa90b7)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>