[SCSI] remove can_power_off flag from scsi_device

Commit 166a2967 "libata: tell scsi layer
device supports runtime power off" introduced the can_power_off flag for
scsi_device and is used to support ZPODD implementation in SCSI layer.
Since ZPODD is now implemented in ATA layer, that flag is no longer
needed, so remove it.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

include/scsi/scsi_device.h

@@ -157,7 +157,6 @@ struct scsi_device {
 	unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
 	unsigned try_rc_10_first:1;	/* Try READ_CAPACACITY_10 first */
 	unsigned is_visible:1;	/* is the device visible in sysfs */
-	unsigned can_power_off:1; /* Device supports runtime power off */
 	unsigned wce_default_on:1;	/* Cache is ON by default */
 	unsigned no_dif:1;	/* T10 PI (DIF) should be disabled */