regulatory: remove BUG_ON

This code is a bit too BUG_ON happy, remove all
instances and while doing so make some code a bit
smarter by passing the right pointer instead of
indices into arrays.

Acked-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --cc net/wireless/nl80211.c
Simple merge

diff --cc net/wireless/reg.c
Simple merge