drm/xe/gsc: Fix double-free of managed BO in error path

In the Linux kernel, the following vulnerability has been resolved:

drm/xe/gsc: Fix double-free of managed BO in error path

The error path in xe_gsc_init_post_hwconfig() explicitly frees a BO

allocated with xe_managed_bo_create_pin_map() via

xe_bo_unpin_map_no_vm(). Since the managed BO already has a devm

cleanup action registered, this causes a double-free when devm

unwinds during probe failure.

Remove the explicit free and let devm handle it, consistent with

all other xe_managed_bo_create_pin_map() callers.

(cherry picked from commit 71d61e3e299a17139e47f980a4d6f425b2c59bf7)