->getevents() should take unsigned args

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/engines/syslet-rw.c b/engines/syslet-rw.c
index e4ccb95..8f2c415 100644
--- a/engines/syslet-rw.c
+++ b/engines/syslet-rw.c
@@ -99,8 +99,8 @@
 	} while (1);
 }
 
-static int fio_syslet_getevents(struct thread_data *td, int min,
-				int fio_unused max,
+static int fio_syslet_getevents(struct thread_data *td, unsigned int min,
+				unsigned int fio_unused max,
 				struct timespec fio_unused *t)
 {
 	struct syslet_data *sd = td->io_ops->data;