Revert "gssd: Fix handling of the gssname=<name> NFS mount option"

This reverts commit c33509d49a6fdcf86ef280a78f428d3cb7012c4a.

It turns out that the long 27 second delay I saw in the
gss_acquire_cred() call was caused by a (mis)configured
DNS. Although I did not specify "dns" in /etc/nsswitch.conf,
I did have a /etc/resolv.conf file on the system (left
there by wpa_supplicant). As such, with no route, it was
somehow trying to contact the DNS server, although there was none.

Once I got rid of the /etc/resolv.conf file, it worked
as expected.

Since there is now a large 5 minute timeout on the
kernel to gssd(8) upcalls, the gssd(8) daemon will not
get terminated when this delay occurs and the only affect
is a 30 second delay during the mount.

Discussed with: bjk