lxcmap: Format host values as "(localhost)"
lxcmap: Format host values as "(localhost)"

The string-representation of lxcmap entries that purely identify that
the address belongs to the local host is overly verbose, given that it
only holds one bit of information: The fact that the IP belongs to the
host. Return a simple string representation for this case.

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@covalent.io>

scanf/cilium,eloycoto/cilium,tgraf/cilium,scanf/cilium,michi-covalent/cilium,cilium-team/cilium,cilium/cilium,scanf/cilium,michi-covalent/cilium,eloycoto/cilium,tklauser/cilium,tgraf/cilium,eloycoto/cilium,scanf/cilium,scanf/cilium,tgraf/cilium,cilium/cilium,cilium/cilium,eloycoto/cilium,eloycoto/cilium,scanf/cilium,michi-covalent/cilium,eloycoto/cilium,tklauser/cilium,cilium-team/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,eloycoto/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,scanf/cilium,tklauser/cilium,cilium/cilium,cilium/cilium