At enslavement time, the primary slave might not be activated if
there is already an active slave and the new slave is the primary.
Replaced complicated logic with a call to bond_select_active_slave(),
which does the right thing.

	Fixes http://bugzilla.kernel.org/show_bug.cgi?id=6378Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>