bonding: fix locking in sysfs primary/active selection

	Fix the functions that store the primary and active slave
options via sysfs to hold the correct locks in the correct order.

	The bond_change_active_slave and bond_select_active_slave
functions both require rtnl, bond->lock for read and curr_slave_lock for
write_bh, and no other locks.  This is so that the lower level
mode-specific functions (notably for balance-alb mode) can release locks
down to just rtnl in order to call, e.g., dev_set_mac_address with the
locks it expects (rtnl only).

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>