IBSS: fix RSN key initialisation

Antonio reported that RSN IBSS failed to work.
We traced it down to a GTK failure, and he then
bisected it to commit bdffdc5ddb0c838af4c90d11:
"AP: Reorder WPA/Beacon initialization".

The reason this commit broke it is that the state
machine's GInit variable is never set to false as
wpa_init_keys() never gets called, and thus new
keys are generated every time the state machine
executes.

Fix this by calling wpa_init_keys() when the new
group has been initialised.

Reported-by: Antonio Quartulli <ordex@autistici.org>
Tested-by: Antonio Quartulli <ordex@autistici.org>
Signed-hostap: Johannes Berg <johannes.berg@intel.com>

wpa_supplicant/ibss_rsn.c

@@ -339,6 +339,8 @@ static int ibss_rsn_auth_init_group(struct ibss_rsn *ibss_rsn,
 		return -1;
 	}
 
+	wpa_init_keys(ibss_rsn->auth_group);
+
 	return 0;
 }