drivers: staging: rtl8187se: refactor wmm_param_update

The function rtl8180_wmm_param_update contained two blocks of code which
were nearly identical. This patch combines those two blocks into a
single function, to reduce code duplication, and do fix some
checkpatch.pl warnings about excessively long lines due to the large
number of indents that were needed for the original blocks of code.

Signed-off-by: Axel Rasmussen <axel.rasmussen1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>