staging: wlan-ng: fix line style warnings in p80211netdev.c

This patch fix the following checkpatch.pl warnings in p80211netdev.c:
WARNING: line over 80 characters

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