SOCK_DGRAM (i.e. UDP), respect the value configured earlier. This allows
TCP NFS root mounts using e.g. the boot.nfsroot.options="tcp" tunable.
In this case some of the connection parameters like the retry timer were
previously set appropriately for TCP but inappropriately for the UDP
socket that was actually used, leading to e.g. extremely long recovery
times (O(hours)) after a nfs server reboot.
Reviewed by: mohans
MFC After: 2 weeks