Staging: r8187se: Fix a faulty if and do additional cleanups

Cleanup the driver and fix a faulty if statement.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Tested by: Bernhard Schiffner <bernhard@schiffner-limbach.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>