drm/xe: Fix potential deadlock in __fini_dbm

drm/xe: Fix potential deadlock in __fini_dbm

If Doorbell Manager is in unclean state during fini phase, for
debug purposes we try to print it's state, but we missed the fact
that we are already holding a lock so the xe_guc_db_mgr_print()
will deadlock since it also attempts to grab the same lock.

Fixes: 587c73343ac7 ("drm/xe: Introduce GuC Doorbells Manager")
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Reviewed-by: Piotr Piórkowski <piotr.piorkowski@intel.com>
Link: https://lore.kernel.org/r/20240111185603.673-1-michal.wajdeczko@intel.com
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>