Add a get_jobs_eta() to return jobs eta information

We duplicate this code in eta.c and server.c, consolidate it.

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/server.c b/server.c
index e20f592..76b6b54 100644
--- a/server.c
+++ b/server.c
@@ -666,22 +666,14 @@
 static int handle_send_eta_cmd(struct fio_net_cmd *cmd)
 {
 	struct jobs_eta *je;
-	size_t size;
 	uint64_t tag = cmd->tag;
+	size_t size;
 	int i;
 
-	if (!thread_number)
+	je = get_jobs_eta(1, &size);
+	if (!je)
 		return 0;
 
-	size = sizeof(*je) + THREAD_RUNSTR_SZ;
-	je = malloc(size);
-	memset(je, 0, size);
-
-	if (!calc_thread_status(je, 1)) {
-		free(je);
-		return 0;
-	}
-
 	dprint(FD_NET, "server sending status\n");
 
 	je->nr_running		= cpu_to_le32(je->nr_running);