[CIFS] Fix set file size to zero when doing chmod to Samba 3.0.26pre

In fixing a bug Samba 3.0.26pre allowed some clients (including Linux cifs
client) to change file size to zero in SET_FILE_UNIX_BASIC (which Linux cifs
client uses for chmod).

The server has been "fixed" now but that also fixes the client to net send
file size zero on chmod.

Fixes Samba bugzilla bug # 4418.

Fixed with help from Jeremy Allison

Signed-off-by: Jeremy Allison <jra@samba.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index 2498d64..0efdf35 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -220,6 +220,9 @@
  */
 #define CIFS_NO_HANDLE        0xFFFF
 
+#define NO_CHANGE_64          0xFFFFFFFFFFFFFFFFULL
+#define NO_CHANGE_32          0xFFFFFFFFUL
+
 /* IPC$ in ASCII */
 #define CIFS_IPC_RESOURCE "\x49\x50\x43\x24"