[CIFS] Allow null user connections

Some servers are configured to only allow null user mounts for
guest access.  Allow nul user (anonymous) mounts e.g.
	mount -t cifs //server/share /mnt -o username=

Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index 1eb9a2e..50afab8 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -1,6 +1,9 @@
 Version 1.46
 ------------
 Support deep tree mounts.  Better support OS/2, Win9x (DOS) time stamps.
+Allow null user to be specified on mount ("username="). Do not return
+EINVAL on readdir when filldir fails due to overwritten blocksize
+(fixes FC problem)
 
 Version 1.45
 ------------