netdevsim: correctly check return value of debugfs_create_dir

- Checking return value with IS_ERROR_OR_NULL
- Added error handling where it was not handled

Signed-off-by: Prashant Bhole <[e-mail]>
Acked-by: Jakub Kicinski <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/netdevsim/bpf.c

···
 {
 	struct nsim_bpf_bound_prog *state;
 	char name[16];
-	int err;
 
 	state = kzalloc(sizeof(*state), GFP_KERNEL);
 	if (!state)
···
 	/* Program id is not populated yet when we create the state. */
 	sprintf(name, "%u", ns->prog_id_gen++);
 	state->ddir = debugfs_create_dir(name, ns->ddir_bpf_bound_progs);
-	if (IS_ERR(state->ddir)) {
-		err = PTR_ERR(state->ddir);
+	if (IS_ERR_OR_NULL(state->ddir)) {
 		kfree(state);
-		return err;
+		return -ENOMEM;
 	}
 
 	debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id);
···
 			   &ns->bpf_bind_verifier_delay);
 	ns->ddir_bpf_bound_progs =
 		debugfs_create_dir("bpf_bound_progs", ns->ddir);
+	if (IS_ERR_OR_NULL(ns->ddir_bpf_bound_progs))
+		return -ENOMEM;
 
 	ns->bpf_tc_accept = true;
 	debugfs_create_bool("bpf_tc_accept", 0600, ns->ddir,

drivers/net/netdevsim/netdev.c

···
 
 	ns->netdev = dev;
 	ns->ddir = debugfs_create_dir(netdev_name(dev), nsim_ddir);
+	if (IS_ERR_OR_NULL(ns->ddir))
+		return -ENOMEM;
 
 	err = nsim_bpf_init(ns);
 	if (err)
···
 	int err;
 
 	nsim_ddir = debugfs_create_dir(DRV_NAME, NULL);
-	if (IS_ERR(nsim_ddir))
-		return PTR_ERR(nsim_ddir);
+	if (IS_ERR_OR_NULL(nsim_ddir))
+		return -ENOMEM;
 
 	err = bus_register(&nsim_bus);
 	if (err)