Fix extended security auth failure

Fix authentication failures using extended security mechanisms.
cifs client does not take into consideration extended security bit
in capabilities field in negotiate protocol response from the server.

Please refer to Samba bugzilla 8046.

Reported-and-tested by: Werner Maes <Werner.Maes@icts.kuleuven.be>
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>