drm/xe/uc: Don't emit false error if running in execlist mode

When running in execlist mode (using force_execlist=1 modparam)
we incorrectly select the error path in xe_uc_init(), leading to
an unwanted error message like this:

[ ] xe 0000:00:00.0: [drm] *ERROR* GT0: Failed to initialize uC (0000000000000000)

Fix that by doing early return like we do in other similar cases.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240521114857.712-1-michal.wajdeczko@intel.com

drivers/gpu/drm/xe/xe_uc.c

@@ -51,7 +51,7 @@ int xe_uc_init(struct xe_uc *uc)
 		goto err;
 
 	if (!xe_device_uc_enabled(uc_to_xe(uc)))
-		goto err;
+		return 0;
 
 	ret = xe_wopcm_init(&uc->wopcm);
 	if (ret)