wi driver ad-hoc demo mode

[Simas Kvilius]

I'm using old Lucent orinoco wireless card in ad-hoc demo mode.
It seems someone forgot to implement ad-hoc demo mode in the newest wi
driver (driver which comes with RELENG7). I added  following statement
to if_wi.c line 407 to indicate, that my card supports ad-hoc demo
mode (someone definitely forgot to include this):

ic->ic_caps |= IEEE80211_C_AHDEMO;

Now I can enable ad-hoc demo mode using ifconfig utility (with command
ifconfig wi0 mode 11b media DS/11Mbps mediaopt adhoc mediaopt flag0),
but it seems there is another bug. Now I cannot change radio channel
(nic is always stuck in channel 3, i think this channel is hardcoded
as default ibss channel inside my nic).
Could anyone fix this bug with channels (I tried to figure out where
problem is, but it seems I'm to lame to do kernel hacking of this
level by myself). My card was working fine with FreeBSD 5.1 (both with
ifconfig and wicontrol tools) and Linux.

Regards,
Simas