drm/xe: Change return type to void for xe_force_wake_put

There is no need to return an error from xe_force_wake_put(), as a
failure implicitly indicates that the domain failed to sleep.

v3
- Move kernel-doc to this patch (Badal)

v5
- change parameter to unsigned int in xe_force_wake_put()

v6
- Remove unneccsary wrapping (Michal)
- Remove non required header (Michal)
- Mention timeout(Michal)

v8
- Fix kernel-doc

Cc: Michal Wajdeczko <[e-mail]>
Cc: Badal Nilawar <[e-mail]>
Cc: Rodrigo Vivi <[e-mail]>
Cc: Lucas De Marchi <[e-mail]>
Cc: Nirmoy Das <[e-mail]>
Reviewed-by: Badal Nilawar <[e-mail]>
Signed-off-by: Himal Prasad Ghimiray <[e-mail]>
Reviewed-by: Michal Wajdeczko <[e-mail]>
Reviewed-by: Nirmoy Das <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Signed-off-by: Rodrigo Vivi <[e-mail]>

drivers/gpu/drm/xe/xe_force_wake.c

···
 	return ref_incr;
 }
 
-int xe_force_wake_put(struct xe_force_wake *fw,
-		      unsigned int fw_ref)
+/**
+ * xe_force_wake_put - Decrement the refcount and put domain to sleep if refcount becomes 0
+ * @fw: Pointer to the force wake structure
+ * @fw_ref: return of xe_force_wake_get()
+ *
+ * This function reduces the reference counts for domains in fw_ref. If
+ * refcount for any of the specified domain reaches 0, it puts the domain to sleep
+ * and waits for acknowledgment for domain to sleep within 50 milisec timeout.
+ * Warns in case of timeout of ack from domain.
+ */
+void xe_force_wake_put(struct xe_force_wake *fw, unsigned int fw_ref)
 {
 	struct xe_gt *gt = fw->gt;
 	struct xe_force_wake_domain *domain;
···
 	 * in error path of individual domains.
 	 */
 	if (!fw_ref)
-		return 0;
+		return;
 
 	if (xe_force_wake_ref_has_domain(fw_ref, XE_FORCEWAKE_ALL))
 		fw_ref = fw->initialized_domains;
···
 
 	xe_gt_WARN(gt, ack_fail, "Forcewake domain%s %#x failed to acknowledge sleep request\n",
 		   str_plural(hweight_long(ack_fail)), ack_fail);
-	return ack_fail;
 }

drivers/gpu/drm/xe/xe_force_wake.h

···
 				struct xe_force_wake *fw);
 unsigned int __must_check xe_force_wake_get(struct xe_force_wake *fw,
 					    enum xe_force_wake_domains domains);
-int xe_force_wake_put(struct xe_force_wake *fw,
-		      unsigned int fw_ref);
+void xe_force_wake_put(struct xe_force_wake *fw, unsigned int fw_ref);
 
 static inline int
 xe_force_wake_ref(struct xe_force_wake *fw,