staging: ks7010: refactor hostif_sme_set_rsn function

This commit make use of two introduced local variables
to make more readable code of hostif_sme_set_rsn function.
It just assign those local variables in different cases
where are needed and extract common code to assign them
at the end.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>