Terminate clients when 'Disconnect' is clicked

And reports errors in error bar.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/client.h b/client.h
index a68507f..de6c197 100644
--- a/client.h
+++ b/client.h
@@ -95,5 +95,7 @@
 extern int fio_client_add(const char *, void **);
 extern struct fio_client *fio_client_add_explicit(const char *, int, int);
 extern void fio_client_add_cmd_option(void *, const char *);
+extern void fio_clients_terminate(void);
+
 #endif