vrrpd: be less smart about interface state

vrrpd: be less smart about interface state

Stop caring about interface state so much. It's screwing up autoconfig
because Zebra's message semantics are pretty much absolute nonsense when
it comes to indicating interface state.

This change will cause us to do things like attempt to transmit
advertisements on a down interface, but I'd rather have the user see
those error messages in the log file than force them to fight vrrpd to
convince it that, yes, they actually do want a VRRP instance created.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>