bonding: process the err returned by dev_set_allmulti properly in bond_enslave

bonding: process the err returned by dev_set_allmulti properly in bond_enslave

commit 9f5a90c107741b864398f4ac0014711a8c1d8474 upstream.

When dev_set_promiscuity(1) succeeds but dev_set_allmulti(1) fails,
dev_set_promiscuity(-1) should be done before going to the err path.
Otherwise, dev->promiscuity will leak.

Fixes: 7e1a1ac1fbaa ("bonding: Check return of dev_set_promiscuity/allmulti")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>