MCLAG sync FDB MAC from STATE_DB

[jianjundong]

What I did Previous implement: Mclagsyncd read MACs from ASIC_DB every 1 minute, and notify the MAC changes to ICCPd. FDB entries learned from MC-LAG enabled port-channel will be synced up with peer.

Currently implement: When fdborch is notified that FDB MAC is changed, it will store the changes to STATE_DB. Mclagsyncd is the consumer of the table FDB_TABLE in STATE_DB, and it will notify the MAC changes to ICCPd. FDB entries learned from MC-LAG enabled port-channel will be synced up with peer.

Why I did it Mclagsyncd reading MAC periodically every minute consumes system CPU.

How I verified it Complie and test it on nephos lab

Details if related This PR must work with the following PR. Layer 2 Forwarding Enhancements #885

[lgtm-com[bot]]

This pull request fixes 4 alerts when merging 9b54c5cab52e39fd609d7349b20c40344b29fca5 into 3c8289b68da2d5ef4e2cc275df2426f01a84a3d3 - view on LGTM.com

fixed alerts:

• 2 for Resource not released in destructor
• 2 for 'new[]' array freed with 'delete'

[lgtm-com[bot]]

This pull request fixes 4 alerts when merging 18b50c1c0ac97ce664fd4a1908ebdb6b78be9bf9 into 727a518159a08e245f6f37d58f796f2b9097774a - view on LGTM.com

fixed alerts:

• 2 for Resource not released in destructor
• 2 for 'new[]' array freed with 'delete'