bonding: init notify_work earlier to avoid uninitialized use

If bond_kobj_init() or later kzalloc() in bond_alloc_slave() fail,
then we call kobject_put() on the slave->kobj. This in turn calls
the release function slave_kobj_release() which will always try to
cancel_delayed_work_sync(&slave->notify_work), which shouldn't be
done on an uninitialized work struct.

Always initialize the work struct earlier to avoid problems here.

Syzbot bisected this down to a completely pointless commit, some
fault injection may have been at work here that caused the alloc
failure in the first place, which may interact badly with bisect.

Reported-by:  <syzbot+bfda097c12a00c8cae67@syzkaller.appspotmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>