conman:  Fix a logging bug about attempts to join the WLAN.

conman incorrectly treated all "wifi setclient" 0 return codes as
indicating successful association.  This ignored the case in which
wpa_supplicant is already running with the specified config, in which
case /bin/wifi returns 0 without touching wpa_supplicant, even if
wpa_supplicant is not associated.

Bug: 34741612

Change-Id: I76911ae0291c834841602fa3038436010a5ac292
1 file changed