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: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>