LogAnalyser failures in ARP tests : arp/test_arp_garp_no_update, arp/testNeighborMacNoPtf

[judyjoseph]

Description

Errors seen during ARP run tests in Chassis with multi-asic linecards. This happens when neighbors learned in an asic is getting programmed in the other asic. The command used is "ip neigh add" which fails if there is already an entry present and the mac address is getting changed.

Steps to reproduce the issue:

1. Run the tests test_arp_garp_no_update/testNeighborMacNoPtf

Describe the results you received:
The tests fail with error

2022-07-31T04:29:25.5850517Z E               Match Messages:
2022-07-31T04:29:25.5853685Z E               Jul 31 04:21:17.084414 str2--lc1-1 ERR swss0#nbrmgrd: :- addKernelNeigh: Failed to add Nbr for 29.0.0.2, error: 2
2022-07-31T04:29:25.5856493Z E               
2022-07-31T04:29:25.5859585Z E               Jul 31 04:21:17.084634 str2--lc1-1 ERR swss1#nbrmgrd: :- addKernelNeigh: Failed to add Nbr for 29.0.0.2, error: 2
2022-07-31T04:29:25.5862339Z E               
2022-07-31T04:29:25.5865290Z E               Jul 31 04:21:18.091901 str2--lc1-1 ERR swss0#nbrmgrd: :- addKernelRoute: Failed to add route for 29.0.0.2, error: 2
2022-07-31T04:29:25.5868104Z E               
2022-07-31T04:29:25.5871219Z E               Jul 31 04:21:18.091901 str2--lc1-1 ERR swss0#nbrmgrd: :- doStateSystemNeighTask: Route entry add on dev Ethernet-IB0 failed for 'str2--lc2-1|asic0|PortChannel101|29.0.0.2'
2022-07-31T04:29:25.5874081Z E               
2022-07-31T04:29:25.5877060Z E               Jul 31 04:21:18.093208 str2--lc1-1 ERR swss1#nbrmgrd: :- addKernelRoute: Failed to add route for 29.0.0.2, error: 2
2022-07-31T04:29:25.5879799Z E               
2022-07-31T04:29:25.5882955Z E               Jul 31 04:21:18.093208 str2--lc1-1 ERR swss1#nbrmgrd: :- doStateSystemNeighTask: Route entry add on dev Ethernet-IB1 failed for 'str2--lc2-1|asic0|PortChannel101|29.0.0.2'

Describe the results you expected:
The tests should pass.

Additional information you deem important:

**Output of `show version`:**

```
(paste your output here)
```

**Attach debug file `sudo generate_dump`:**

```
(paste your output here)
```

[sanmalho-git]

@judyjoseph - do we expect a fix in sonic-buildimage to not print the error messages, or a fix in sonic-mgmt tests to extend the logAnalyzer to ignore these messages

[judyjoseph]

@sanmalho-git I have this PR raised for fixing it with changing the log messages in sonic-swss, sonic-net/sonic-swss#2416

[yxieca]

@judyjoseph can you close this issue if the fix has be merged and validated?

[judyjoseph]

@yxieca The fix is in sonic-swss/master, still getting pulled into sonic-buildimage via this PR : sonic-net/sonic-buildimage#11884. I will close this PR once that is merged.