bgp_labeled_safi doesn't cover all labelled safi types

[louberger]

bgp_labeled_safi should wither just cover the UNICAST case or should include EVPN. Usage is inconsistent as sometimes code post check assumes UNICAST and other times then makes explicit checks for EVPN. This should be make consistent, i.e., include all safit types that support labels and calling code needs to be modified as appropriate.

static inline int
bgp_labeled_safi (safi_t safi)
{
if ((safi == SAFI_LABELED_UNICAST) || (safi == SAFI_MPLS_VPN))
return 1;
return 0;
}

[donaldsharp]

This will probably be addressed by bug #473

[louberger]

I think this is addressed by recent PRs.