ping: By default, don't reverse lookup IP addresses

ping: By default, don't reverse lookup IP addresses

ping's default is now not to attempt reverse DNS lookups.  The -H flag will
enable them.  This change is not quite a reversion of r351330.  That change
made the happy path and error path do reverse lookups consistently; this
change changes the default for both paths.

Submitted by:	Ján Sučan <sucanjan@gmail.com>
Discussed with:	cem
MFC after:	2 weeks
MFC-With:	351330
Sponsored by:	Google LLC (Google Summer of Code 2019)
Differential Revision:	https://reviews.freebsd.org/D21364