Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 215c225..c4deecc 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -23,7 +23,8 @@
 {
 	struct kernfs_node *kn, *target = NULL;
 
-	BUG_ON(!name || !parent);
+	if (WARN_ON(!name || !parent))
+		return -EINVAL;
 
 	/*
 	 * We don't own @target_kobj and it may be removed at any time.