its-g5: Fix coding style according to the checkpatch.pl report

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Add kerneldoc comments

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Besides the WARN_ON terminate the function execution

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Simplify struct initialization to all 0's

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: No reason to use the channel context exclusively

"There is no reason for using the channel context exclusively
since the channel is fixed, and doesn't change like in
IBSS, afaict? IBSS needs this, but only because it might
change the channel on the fly."
-- J. Berg

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Add new fields to the end of the enum only -- this is ABI

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Define bssid_wildcard only locally for one occurence

Use appropriate "broadcast_ether_addr" functions where
possible.

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Do not mix "new" 5/10 MHz channels with "old channel type" functions

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Since join() handles the channel setting, this is incorrect

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Remove dead code / comments

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
its-g5: Must be atomic

Backtrace:
ieee80211_ocb_rx_no_sta()
prepare_for_handlers()
ieee80211_prepare_and_rx_handle()
__ieee80211_rx_handle_packet()

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>