Separate out __ata_ehi_hotplugged() from ata_ehi_hotplugged().  The
underscored version doesn't set AC_ERR_ATA_BUS.  This will be used for
resume which is a hotplug event but not an ATA bus error.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>