ospf6d: Intra-prefix LSA update after frr restart

ospf6d: Intra-prefix LSA update after frr restart

Initially INP LSA is originated, when connected
interface comes up. As neighbor is not up, LSA is
not transmitted but stored in DB.
As NSM transition to FULL, INP is scheduled but
ospf6_flood() would not originate the LSA as
current DB and new INP LSA same so it discards
the new LSA.
When Neighor becomes FULL, originate INP via
flushing current DB copy and generate new.
This is introduced as PR 1738 introduce,
premature aging of LSAs in nbr table as R1
going down. upon neigbor coming up, INP was
not updated to new age.

Ticket:CM-19926,CM-19945
Testing Done:

Topology R3 --- R1 -- R2, R1 have INP LSA.
After frr restart R2 and R3 re learnt R1's
INP LSA as new neighbor(s) come up.

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