mac80211, hostapd: Fix macfilter for multi bssid setups

Previously only the first macfilter configuration would have been used
on all interfaces. However, the configuration was always done per vif
already. Hence, move the macfilter setup into hostapd.sh where and
create one mac list file per vif.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>

SVN-Revision: 34470