[SCSI] libsas: fix ata_eh clobbering ex_phys via smp_ata_check_ready
The check_ready implementation in the expander-attached ata device case
polls on sas_ex_phy_discover(). The effect is that the ex_phy fields
(critically ->attached_sas_addr) can change. When ata_eh ends and
libsas comes along to revalidate the domain
sas_unregister_devs_sas_addr() can fail to lookup devices to remove, or
fail to re-add an ata device that ata_eh marked as disabled. So change
the code to skip the sas_address and change count updates when ata_eh is
active.
Cc: Jack Wang <jack_wang@usish.com> Tested-by: Maciej Patelczyk <maciej.patelczyk@intel.com> Tested-by: Bartek Nowakowski <bartek.nowakowski@intel.com> Tested-by: Jacek Danecki <jacek.danecki@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>