staging: rtl8192e: fix coding style errors (macros in parentheses)

Fix checkpatch.pl errors 'Macros with complex values should be enclosed in parentheses'.

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>