cifs: convert cifs_iovec_write to use async writes

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 57ce6f8..96192c1 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -483,6 +483,8 @@
 /* asynchronous write support */
 struct cifs_writedata {
 	struct kref			refcount;
+	struct list_head		list;
+	struct completion		done;
 	enum writeback_sync_modes	sync_mode;
 	struct work_struct		work;
 	struct cifsFileInfo		*cfile;