td_verror() needs errno style error

put_file_log() could pass in -1, we need the actual error instead.

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/io_u.c b/io_u.c
index 411da32..4b0b5a7 100644
--- a/io_u.c
+++ b/io_u.c
@@ -678,7 +678,7 @@
 
 void put_file_log(struct thread_data *td, struct fio_file *f)
 {
-	int ret = put_file(td, f);
+	unsigned int ret = put_file(td, f);
 
 	if (ret)
 		td_verror(td, ret, "file close");