wireless: remove superfluous if statement in regulatory code

Commit eeca9fce ('cfg80211: Schedule timeout for all CRDA calls')
left behind a superfluous check after it removed some earlier code.

In reg_process_hint, the test of "treatment == REG_REQ_IGNORE ||
treatment == REG_REQ_ALREADY_SET" is superfluous because the code in the
if-then branch is identical to the code after the if statement.

Coverity CID #1295939

I also removed the unnecessary assignment of treatment in this case,
and added a comment reminding any future patch authors to ensure that
treatment is properly assigned before it is used after the switch.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>