zebra: Fix to avoid two Vrfs with same table ids

zebra: Fix to avoid two Vrfs with same table ids

During internal testing, when the following sequence is followed, two
non default vrfs end up pointing to the same table-id

 - Initially vrf201 has table id 1002
 - ip link add dev vrf202 type vrf table 1002
 - ip link set dev vrf202 up
 - ip link set dev <intrerface> master vrf202

This will ideally lead to zebra exit since this is a misconfiguration as
expected.

However if we perform a restart frr.service at this point, we end up
having two vrfs pointing to same table-id and bad things can happen.
This is because in the interface_vrf_change, we incorrectly check for
vrf_lookup_by_id() to evaluate if there is a misconfig. This works well
for a non restart case but not for the startup case.

root@mlx-3700-20:mgmt:/var/log/frr# sudo vtysh -c "sh vrf"
vrf mgmt id 37 table 1001
vrf vrf201 id 46 table 1002
vrf vrf202 id 59 table 1002 >>>>

Fix: in all cases of misconfiguration, exit zebra as expected.

Ticket :#3970414

Signed-off-by: Donald Sharp <sharpd@nvidia.com>
Signed-off-by: Rajasekar Raja <rajasekarr@nvidia.com>