Do not call afs_MarinerLog when afs_mariner is not set

Do not call afs_MarinerLog when afs_mariner is not set

When mariner log is not set up (afs_mariner=0), do not call afs_MarinerLog,
otherwise a osi_NetSend() to hostaddress=0 is tried, which will give you
ICMP messages in the socket error queue.
Do not call afs_AddMarinerName, when afs_mariner is not set.

Change-Id: I1ed6369fb0eea130348f4f6fd37bb0d021c4c791
Reviewed-on: http://gerrit.openafs.org/8519
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>