usb: microtek possible memleak fix

Possible memleak fix on error path. The changes:

- out_kfree2 and out_free_urb replaced
- missing scsi_host_put() added

Here it goes:

Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>