Fix problem with iodepth_batch_complete=0 and accounting

If the queue is full, we always need to reap at least one event.
Otherwise we end up failing get_io_u() and restarting the file.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/backend.c b/backend.c
index 7343286..a9885c6 100644
--- a/backend.c
+++ b/backend.c
@@ -494,7 +494,10 @@
 		if (full || !td->o.iodepth_batch_complete) {
 			min_events = min(td->o.iodepth_batch_complete,
 					 td->cur_depth);
-			if (full && !min_events && td->o.iodepth_batch_complete != 0)
+			/*
+			 * if the queue is full, we MUST reap at least 1 event
+			 */
+			if (full && !min_events)
 				min_events = 1;
 
 			do {
@@ -676,7 +679,10 @@
 		if (full || !td->o.iodepth_batch_complete) {
 			min_evts = min(td->o.iodepth_batch_complete,
 					td->cur_depth);
-			if (full && !min_evts && td->o.iodepth_batch_complete != 0)
+			/*
+			 * if the queue is full, we MUST reap at least 1 event
+			 */
+			if (full && !min_evts)
 				min_evts = 1;
 
 			if (__should_check_rate(td, 0) ||