man: improvements to language for astraceroute.8

Signed-off-by: Stephen Wadeley <swadeley@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
man: improvements to astraceroute.8, inconsistent use of and ''

Signed-off-by: Stephen Wadeley <swadeley@redhat.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
man: astraceroute: minor: remove two trailing whitespaces

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>