Tear down sysctls only after detaching children. This lets you enable

debugging while detaching hangs.

sys/dev/iscsi/iscsi_main.c

@@ -663,12 +663,12 @@ iscsi_modcmd(modcmd_t cmd, void *arg)
 
 	case MODULE_CMD_FINI:
 #ifdef _MODULE
-		sysctl_teardown(&clog);
-
 		error = config_cfdata_detach(iscsi_cfdata);
 		if (error)
 			return error;
 
+		sysctl_teardown(&clog);
+
 		config_cfattach_detach(iscsi_cd.cd_name, &iscsi_ca);
 		config_cfdriver_detach(&iscsi_cd);
 		devsw_detach(NULL, &iscsi_cdevsw);