Windows: No network, no probe

Windows: No network, no probe

Modify cm_PingServer and cm_CheckServersMulti to avoid probing servers
when there are no network interfaces with which to do so.  Just mark
the servers down.

Reviewed-on: http://gerrit.openafs.org/11446
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit ac601314706043f623ace379e3da597a7d5c5e9a)

Change-Id: I41ec7269af762abcdc54ea6c59320f1f6c05e89c
Reviewed-on: http://gerrit.openafs.org/11497
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>