[CIFS] Fix oops in cifs_create when nfsd server exports cifs mount

nfsd is passing null nameidata (probably the only one doing that)
on call to create - cifs was missing one check for this.

Note that running nfsd over a cifs mount requires specifying fsid on
the nfs exports entry and requires mounting cifs with serverino mount
option.

Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index ee276f6..f92e0ee 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -1,6 +1,7 @@
 Version 1.50
 ------------
-Fix NTLMv2 signing
+Fix NTLMv2 signing. NFS server mounted over cifs works (if cifs mount is
+done with "serverino" mount option).
 
 Version 1.49
 ------------