After the gcc4 switch the stack protector triggers in atw when a buffer is overflowed.  Fix this and increase the size of the rate buffer (which is still < IEEE80211_RATE_MAXSIZE due to hardware restrictions) while here.
After the gcc4 switch the stack protector triggers in atw
when a buffer is overflowed.  Fix this and increase the
size of the rate buffer (which is still < IEEE80211_RATE_MAXSIZE
due to hardware restrictions) while here.

ok claudio@ damien@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars