- A channel being defined is currently "channel is not null". APIs can return a NULL channel if there's no channel available to match some criteria.
- A channel being defined as "any channel" is NOT NULL and a magic value (0xffff). Deferencing this is obviously bad.
We should be hiding the inner workings of the channel represent /
contents from consumers, and this will let us lay the groundwork
for further detailed checks in the channel macros (ie, avoid
NULL / ANYC dereferencing.)
- create a macros that returns true if the channel is defined (IEEE80211_IS_CHAN_DEFINED())
- create a macro that return true if the channel is the "any channel" (IEEE80211_IS_CHAN_ANYC())
- Convert a couple of places (dfs, vht) over to use the new macros as a test.
This is mostly a test and request for feedback before the rest
of the net80211 stack / drivers are converted.
magic ANYC values, and it's a