Fix eta for pure read workload with verify enabled

Verify doubles the expected IO count, but that is only true if
we are first writing a file and then reading it back to verify.
If the workload running is just reading back data to verify it,
the IO count is already correct.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/eta.c b/eta.c
index 350815e..625b1f8 100644
--- a/eta.c
+++ b/eta.c
@@ -107,7 +107,7 @@
 	 * if writing, bytes_total will be twice the size. If mixing,
 	 * assume a 50/50 split and thus bytes_total will be 50% larger.
 	 */
-	if (td->o.do_verify && td->o.verify) {
+	if (td->o.do_verify && td->o.verify && td_write(td)) {
 		if (td_rw(td))
 			bytes_total = bytes_total * 3 / 2;
 		else