staging: rtl8723bs: clean up clang warning on extraneous parentheses

There are extraneous parantheses that are causing clang to produce a
warning so remove these.

Clean up 3 clang warnings:
equality comparison with extraneous parentheses [-Wparentheses-equality]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>