cgroup: fix error return from cgroup_create()

cgroup_create() was returning 0 after allocation failures.  Fix it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org

kernel/cgroup.c

@@ -4158,7 +4158,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 	struct cgroup *cgrp;
 	struct cgroup_name *name;
 	struct cgroupfs_root *root = parent->root;
-	int ssid, err = 0;
+	int ssid, err;
 	struct cgroup_subsys *ss;
 	struct super_block *sb = root->sb;
 
@@ -4168,8 +4168,10 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 		return -ENOMEM;
 
 	name = cgroup_alloc_name(dentry);
-	if (!name)
+	if (!name) {
+		err = -ENOMEM;
 		goto err_free_cgrp;
+	}
 	rcu_assign_pointer(cgrp->name, name);
 
 	/*
@@ -4177,8 +4179,10 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 	 * a half-baked cgroup.
 	 */
 	cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL);
-	if (cgrp->id < 0)
+	if (cgrp->id < 0) {
+		err = -ENOMEM;
 		goto err_free_name;
+	}
 
 	/*
 	 * Only live parents can have children.  Note that the liveliness