staging: rtl8188eu: checkpatch fixes: unnecessary parentheses removed in hal/bb_cfg.c

This is checkpatch fixes for hal/bb_cfg.c file:
unnecessary parentheses around <expr>.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>