This patch adds the krb5 hostbased principal, name which the

This patch adds the krb5 hostbased principal, name which the
nfs client used to authenticate, to the svcgssd downcall
information.  This information is needed for the callback
authentication.

When estabishing the callback, nfsd will pass the principal
name in the upcall to the gssd.  gssd will acquire a service
ticket for the specified principal name.

Signed-off-by: Olga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Steve Dickson <steved@redhat.com>