Fix passive_scan config parameter writing

Commit c35e35ed8133bb6d7b96765c5f0b1d41efe09fc5 ('Add passive_scan
configuration parameter') used incorrect parameter name when writing the
passive_scan parameter into a configuration file.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
diff --git a/wpa_supplicant/config_file.c b/wpa_supplicant/config_file.c
index cdc6e39..66d170c 100644
--- a/wpa_supplicant/config_file.c
+++ b/wpa_supplicant/config_file.c
@@ -1232,7 +1232,7 @@
 			config->mesh_max_inactivity);
 
 	if (config->passive_scan)
-		fprintf(f, "cert_in_cb=%d\n", config->passive_scan);
+		fprintf(f, "passive_scan=%d\n", config->passive_scan);
 }
 
 #endif /* CONFIG_NO_CONFIG_WRITE */