ipmi: make ipmi_destroy_user() return void

Return value of ipmi_destroy_user() has no meaning, because it's always
zero and callers can do nothing with it. And in most cases it's not
checked. So make this function return void. This also will eliminate static
code analyzer warnings such as unreachable code/redundant comparison when
the return value is checked against non-zero value.

Found by Linux Verification Center (linuxtesting.org) with Svace.

Signed-off-by: Vitaliy Shevtsov <v.shevtsov@maxima.ru>
Message-ID: <20241225014532.20091-1-v.shevtsov@maxima.ru>
Signed-off-by: Corey Minyard <corey@minyard.net>

Author: Vitaliy Shevtsov

drivers/char/ipmi/ipmi_devintf.c

@@ -122,12 +122,9 @@ static int ipmi_open(struct inode *inode, struct file *file)
 static int ipmi_release(struct inode *inode, struct file *file)
 {
 	struct ipmi_file_private *priv = file->private_data;
-	int                      rv;
 	struct ipmi_recv_msg *msg, *next;
 
-	rv = ipmi_destroy_user(priv->user);
-	if (rv)
-		return rv;
+	ipmi_destroy_user(priv->user);
 
 	list_for_each_entry_safe(msg, next, &priv->recv_msgs, link)
 		ipmi_free_recv_msg(msg);

drivers/char/ipmi/ipmi_msghandler.c

@@ -1398,13 +1398,11 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
 	module_put(owner);
 }
 
-int ipmi_destroy_user(struct ipmi_user *user)
+void ipmi_destroy_user(struct ipmi_user *user)
 {
 	_ipmi_destroy_user(user);
 
 	kref_put(&user->refcount, free_user);
-
-	return 0;
 }
 EXPORT_SYMBOL(ipmi_destroy_user);
 

drivers/char/ipmi/ipmi_poweroff.c

@@ -699,18 +699,14 @@ static int __init ipmi_poweroff_init(void)
 #ifdef MODULE
 static void __exit ipmi_poweroff_cleanup(void)
 {
-	int rv;
-
 #ifdef CONFIG_PROC_FS
 	unregister_sysctl_table(ipmi_table_header);
 #endif
 
 	ipmi_smi_watcher_unregister(&smi_watcher);
 
 	if (ready) {
-		rv = ipmi_destroy_user(ipmi_user);
-		if (rv)
-			pr_err("could not cleanup the IPMI user: 0x%x\n", rv);
+		ipmi_destroy_user(ipmi_user);
 		pm_power_off = old_poweroff_func;
 	}
 }

drivers/char/ipmi/ipmi_watchdog.c

@@ -1065,7 +1065,6 @@ static void ipmi_register_watchdog(int ipmi_intf)
 
 static void ipmi_unregister_watchdog(int ipmi_intf)
 {
-	int rv;
 	struct ipmi_user *loc_user = watchdog_user;
 
 	if (!loc_user)
@@ -1090,9 +1089,7 @@ static void ipmi_unregister_watchdog(int ipmi_intf)
 	mutex_lock(&ipmi_watchdog_mutex);
 
 	/* Disconnect from IPMI. */
-	rv = ipmi_destroy_user(loc_user);
-	if (rv)
-		pr_warn("error unlinking from IPMI: %d\n",  rv);
+	ipmi_destroy_user(loc_user);
 
 	/* If it comes back, restart it properly. */
 	ipmi_start_timer_on_heartbeat = 1;

include/linux/ipmi.h

@@ -126,7 +126,7 @@ int ipmi_create_user(unsigned int          if_num,
  * the users before you destroy the callback structures, it should be
  * safe, too.
  */
-int ipmi_destroy_user(struct ipmi_user *user);
+void ipmi_destroy_user(struct ipmi_user *user);
 
 /* Get the IPMI version of the BMC we are talking to. */
 int ipmi_get_version(struct ipmi_user *user,