bonding: Added -ENODEV interpret for slaves option

When the incorrect interface name is stored in the slaves/active_slave
option of the bonding sysfs, the kernel does not record the log that
interface does not exist.

This patch adds a log for -ENODEV error, which will facilitate users to
figure out such issue.
Signed-off-by: NJianlin Lv <Jianlin.Lv@arm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_options.c

@@ -640,6 +640,15 @@ static void bond_opt_error_interpret(struct bonding *bond,
 		netdev_err(bond->dev, "option %s: unable to set because the bond device is up\n",
 			   opt->name);
 		break;
+	case -ENODEV:
+		if (val && val->string) {
+			p = strchr(val->string, '\n');
+			if (p)
+				*p = '\0';
+			netdev_err(bond->dev, "option %s: interface %s does not exist!\n",
+				   opt->name, val->string);
+		}
+		break;
 	default:
 		break;
 	}