bonding: fix reference count leak in balance-alb mode

Commit d5410ac7b0ba ("net:bonding:support balance-alb interface
with vlan to bridge") introduced a reference count leak by not releasing
the reference acquired by ip_dev_find().  Remedy this by insuring the
reference is released.

Fixes: d5410ac7b0ba ("net:bonding:support balance-alb interface with vlan to bridge")
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/26758.1660194413@famine
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
