net: netconsole: Eliminate redundant setting of enabled field

When disabling a netconsole target, enabled_store() is called with
enabled=false. Currently, this results in updating the nt->enabled
field twice:

1. Inside the if/else block, with the target_list_lock spinlock held
2. Later, without the target_list_lock

This patch eliminates the redundancy by setting the field only once,
improving efficiency and reducing potential race conditions.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20240709144403.544099-3-leitao@debian.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/netconsole.c

@@ -369,6 +369,7 @@ static ssize_t enabled_store(struct config_item *item,
 		if (err)
 			goto out_unlock;
 
+		nt->enabled = true;
 		pr_info("network logging started\n");
 	} else {	/* false */
 		/* We need to disable the netconsole before cleaning it up
@@ -381,8 +382,6 @@ static ssize_t enabled_store(struct config_item *item,
 		netpoll_cleanup(&nt->np);
 	}
 
-	nt->enabled = enabled;
-
 	mutex_unlock(&dynamic_netconsole_mutex);
 	return strnlen(buf, count);
 out_unlock: