staging: otus: fix compile warning and some style issues

In today linux-next I got a compile warning in staging/otus driver.
This patch solves the issue and also improves the coding style.

Signed-off-by: Roberto Rodriguez Alcala <rralcala@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1 file changed