scsi: remove incorrect __exit markups

Even if bus is not hot-pluggable, devices can be unbound from the driver
via sysfs, so we should not be using __exit annotations on remove()
methods. The only exception is drivers registered with
platform_driver_probe() which specifically disables sysfs bind/unbind
attributes.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>