staging: rtl8188eu: fix space between function name and '('

This patch fixes checkpatch.pl warning:
WARNING: space prohibited between function name and open parenthesis '('

Signed-off-by: Aastha Gupta <aastha.gupta4104@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>