CHROMIUMOS: wpa_supplicant: be smarter about blacklisting bssid on dissasoc/deauth

CHROMIUMOS: wpa_supplicant: be smarter about blacklisting bssid on dissasoc/deauth

On deauth/disassoc check the reason code before blacklisting the bssid;
there are several cases where a station can safely rejoin so blacklisting
just causes us to do extra work.

BUG=8087
TEST=manual:associate to ap, suspend long enough for ap to drop due to inactivatity, resume and check logs to verify we do not blacklist

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=3a5892a

[Sam Leffler, 2010-11-17 22:23:01]

Codes 6+7 are returned when we send the NullData frame probe on resume.  Code 4
is returned when a station is dropped for being idle.  There are potentially
other codes to add but these are the important ones for optimizing resume.

[Paul Stewart, 2010-11-17 22:30:38]

LGTM.