net: bonding: fix error return code of bond_neigh_init()

When slave is NULL or slave_ops->ndo_neigh_setup is NULL, no error
return code of bond_neigh_init() is assigned.
To fix this bug, ret is assigned with -EINVAL in these cases.

Fixes: 9e99bfefdbce ("bonding: fix bond_neigh_init()")
Reported-by: TOTE Robot <[e-mail]>
Signed-off-by: Jia-Ju Bai <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/bonding/bond_main.c

···
 
 	rcu_read_lock();
 	slave = bond_first_slave_rcu(bond);
-	if (!slave)
+	if (!slave) {
+		ret = -EINVAL;
 		goto out;
+	}
 	slave_ops = slave->dev->netdev_ops;
-	if (!slave_ops->ndo_neigh_setup)
+	if (!slave_ops->ndo_neigh_setup) {
+		ret = -EINVAL;
 		goto out;
+	}
 
 	/* TODO: find another way [1] to implement this.
 	 * Passing a zeroed structure is fragile,