Print IP address of unresponsive server

Before this patch, only the hostname of the server
is printed when it becomes unresponsive.
This might not be helpful, if the IP-Address has
changed since initial mount when the name was
resolved (e.g. because the IPv6-Prefix changed).

This patch adds the cached IP address of the unresponsive server,
to the log message.

Signed-off-by: Arnd Hannemann <arnd@arndnet.de>
Signed-off-by: Steve French <sfrench@localhost.localdomain>