usb-storage: always set the allow_restart flag

This patch (as1000) sets the SCSI allow_restart flag for USB disk
devices.  In theory this should never hurt, and there definitely are
devices out there (such as the Seagate 250-GB external drive) which
need the flag to be set.
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/storage/scsiglue.c

@@ -177,6 +177,10 @@ static int slave_configure(struct scsi_device *sdev)
 		 * is an occasional series of retries that will all fail. */
 		sdev->retry_hwerror = 1;
 
+		/* USB disks should allow restart.  Some drives spin down
+		 * automatically, requiring a START-STOP UNIT command. */
+		sdev->allow_restart = 1;
+
 	} else {
 
 		/* Non-disk-type devices don't need to blacklist any pages