[SCSI] SCSI: remove dev->power.power_state from mesh driver

power.power_state is scheduled for removal.  This patch (as1055)
removes all uses of that field from the SCSI mesh driver.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Paul Mackerras <paulus@au.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>