drm/i915: do not clean GT table on error path

drm/i915: do not clean GT table on error path

The only task of intel_gt_release_all is to zero gt table. Calling
it on error path prevents intel_gt_driver_late_release_all (called from
i915_driver_late_release) to cleanup GTs, causing leakage.
After i915_driver_late_release GT array is not used anymore so
it does not need cleaning at all.

Sample leak report:

BUG i915_request (...): Objects remaining in i915_request on __kmem_cache_shutdown()
...
Object 0xffff888113420040 @offset=64
Allocated in __i915_request_create+0x75/0x610 [i915] age=18339 cpu=1 pid=1454
 kmem_cache_alloc+0x25b/0x270
 __i915_request_create+0x75/0x610 [i915]
 i915_request_create+0x109/0x290 [i915]
 __engines_record_defaults+0xca/0x440 [i915]
 intel_gt_init+0x275/0x430 [i915]
 i915_gem_init+0x135/0x2c0 [i915]
 i915_driver_probe+0x8d1/0xdc0 [i915]

v2: removed whole intel_gt_release_all

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8489
Fixes: bec68cc9ea42 ("drm/i915: Prepare for multiple GTs")
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231115-dont_clean_gt_on_error_path-v2-1-54250125470a@intel.com