'Ping6 TargetIp' is a valid command input but we bail out when TargetIp is a link local address because we would want the user to specify the NIC (via SourceIp) through which he/she would want to ping to TargetIp. This patch updates the help text to mention the same. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Hegde Nagaraj P <nagaraj-p.hegde@hpe.com> Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>