Staging: rtl8188eu: checkpatch.pl warnings removed

Fixed some of the coding style issues reported by checkpatch.pl

Signed-off-by: Faris de Haan <farisdehaan@gmail.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>