USB: microtek usb scanner: Scsi_Cmnd conversion

Converts obsolete typedef'd Scsi_Cmnd into struct scsi_cmnd.

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>