client: don't leak file descriptor on exit

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/client.c b/client.c
index b553b05..86ac8f4 100644
--- a/client.c
+++ b/client.c
@@ -131,6 +131,9 @@
 		fio_client_dec_jobs_eta(client->eta_in_flight, client->ops->eta);
 	}
 
+	close(client->fd);
+	client->fd = -1;
+
 	nr_clients--;
 	sum_stat_clients--;