bgpd: skip evpn remove marked routes from rescan

bgpd: skip evpn remove marked routes from rescan

Skip evpn routes marked for removed from rescan list
when an interface is flapped.

Ticket:CM-24933
Testing Done:
Validated in a scenario where evpn route is marked
for remove as bgp evpn withdrawal is received. Due to
link flap (frr restart of downstream router), the route
was considered for readd via bgp_update. With this
fix, the remove marked routes are skipped from update.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>