Staging: rtl8187se: Fix compilation warnings and procfs directory leak

Fix some warnings during compilation and correct a programming error
that was leaking a directory in /proc.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Bernhard Schiffner <bernhard@schiffner-limbach.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>