Fixup bad logging types

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/engines/e4defrag.c b/engines/e4defrag.c
index d9ddf75..4d87f67 100644
--- a/engines/e4defrag.c
+++ b/engines/e4defrag.c
@@ -92,7 +92,7 @@
 	ed->donor_fd = open(donor_name, O_CREAT|O_WRONLY, 0644);
 	if (ed->donor_fd < 0) {
 		td_verror(td, ed->donor_fd, "io_queue_init");
-		log_err("Can't open donor file %s err:%d", ed->donor_fd);
+		log_err("Can't open donor file %s err:%d", donor_name, ed->donor_fd);
 		free(ed);
 		return 1;
 	}