WPS: Verify wpa_config_set() return value more consistently

Even though this command is very unlikely to fail, in theory, it could
and the WPS connection would fail in such a case. Return more clearer
failure indication in such a case without even trying to start
reassociation.

Signed-hostap: Jouni Malinen <j@w1.fi>

wpa_supplicant/wps_supplicant.c

@@ -938,7 +938,8 @@ int wpas_wps_start_pbc(struct wpa_supplicant *wpa_s, const u8 *bssid,
 		}
 	}
 #endif /* CONFIG_P2P */
-	wpa_config_set(ssid, "phase1", "\"pbc=1\"", 0);
+	if (wpa_config_set(ssid, "phase1", "\"pbc=1\"", 0) < 0)
+		return -1;
 	if (wpa_s->wps_fragment_size)
 		ssid->eap.fragment_size = wpa_s->wps_fragment_size;
 	eloop_register_timeout(WPS_PBC_WALK_TIME, 0, wpas_wps_timeout,
@@ -981,7 +982,8 @@ int wpas_wps_start_pin(struct wpa_supplicant *wpa_s, const u8 *bssid,
 		os_snprintf(val, sizeof(val), "\"pin=%08d dev_pw_id=%u\"",
 			    rpin, dev_pw_id);
 	}
-	wpa_config_set(ssid, "phase1", val, 0);
+	if (wpa_config_set(ssid, "phase1", val, 0) < 0)
+		return -1;
 	if (wpa_s->wps_fragment_size)
 		ssid->eap.fragment_size = wpa_s->wps_fragment_size;
 	eloop_register_timeout(WPS_PBC_WALK_TIME, 0, wpas_wps_timeout,
@@ -1055,7 +1057,8 @@ int wpas_wps_start_reg(struct wpa_supplicant *wpa_s, const u8 *bssid,
 	res = os_snprintf(pos, end - pos, "\"");
 	if (res < 0 || res >= end - pos)
 		return -1;
-	wpa_config_set(ssid, "phase1", val, 0);
+	if (wpa_config_set(ssid, "phase1", val, 0) < 0)
+		return -1;
 	if (wpa_s->wps_fragment_size)
 		ssid->eap.fragment_size = wpa_s->wps_fragment_size;
 	eloop_register_timeout(WPS_PBC_WALK_TIME, 0, wpas_wps_timeout,