staging: rtl8192u: Fix checkpatch.pl warnings

This patch fixes "line over 80 characters" warnings found in the first patch by breaking u4bAcParam's calculation down into a few steps.

Signed-off-by: Koray Gulcu <koray.gulcu@ozu.edu.tr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>