[LLDB] Do not try to canonicalize gethostname() result

This code is trying too hard and failing. Either the result of
gethostname() is canonical or it is not. If it is not, then trying to
canonicalize it is – for various reasons – a lost cause. For example, a
given machine might have multiple network interfaces with multiple
addresses per interface, each with a different canonical name.
Separably, the result of HostInfoPosix::GetHostname() and latency
thereof shouldn't depend on whether networking is up or down or what
network the machine happened to be attached to at any given moment (like
a laptop that travels between work and home).

https://reviews.llvm.org/D67230

llvm-svn: 371596