Add close_files() that closes all files

Renames the current implementation to close_and_free_files(), since
that is what it actually does.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/filesetup.c b/filesetup.c
index b29db3f..3e11c4c 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -520,6 +520,15 @@
 	struct fio_file *f;
 	unsigned int i;
 
+	for_each_file(td, f, i)
+		td_io_close_file(td, f);
+}
+
+void close_and_free_files(struct thread_data *td)
+{
+	struct fio_file *f;
+	unsigned int i;
+
 	dprint(FD_FILE, "close files\n");
 
 	for_each_file(td, f, i) {