staging: rtl8188eu: Remove unneeded parentheses

This patch removes unneeded parentheses from a if statement
for better readability.

This issue is identified by checkpatch.pl

Signed-off-by: Somya Anand <somyaanand214@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>