Sync PlatformNetBSD.cpp with Linux

Summary:
Various changes in logging from log->Printf() to generic LLDB_LOG().

Sponsored by <The NetBSD Foundation>

Reviewers: labath, joerg

Reviewed By: labath

Subscribers: llvm-commits, lldb-commits

Differential Revision: https://reviews.llvm.org/D42912

llvm-svn: 324251