pimd: Do not complain if re-joining an IGMP group

[dwalton76]

Signed-off-by: Daniel Walton dwalton@cumulusnetworks.com

If you cut-n-paste an existing "ip igmp join 233.200.0.0 0.0.0.0"
command under an interface we should not return an error.

[LabN-CI]

💚 Basic BGPD CI results: SUCCESS, 0 tests failed

Results table

_	_
Result	SUCCESS git merge/1194 53d829f
Date	09/18/2017
Start	12:25:07
Finish	12:48:27
Run-Time	23:20
Total	1808
Pass	1808
Fail	0
Valgrind-Errors	0
Valgrind-Loss	0
Details	vncregress-2017-09-18-12:25:07.txt
Log	autoscript-2017-09-18-12:25:41.log.bz2

For details, please contact louberger

[NetDEF-CI]

Continuous Integration Result: SUCCESSFUL

Congratulations, this patch passed basic tests

Tested-by: NetDEF / OpenSourceRouting.org CI System

CI System Testrun URL: https://ci1.netdef.org/browse/FRR-FRRPULLREQ-1699/

This is a comment from an EXPERIMENTAL automated CI system.
For questions and feedback in regards to this CI system, please feel free to email
Martin Winter - mwinter (at) opensourcerouting.org.

---

CLANG Static Analyzer Summary

• Github Pull Request 1194, comparing to Git base SHA a7dd519

No Changes in Static Analysis warnings compared to base

79 Static Analyzer issues remaining.

See details at
https://ci1.netdef.org/browse/FRR-FRRPULLREQ-1699/artifact/shared/static_analysis/index.html

[Jafaral]

What about we keep the warning but return ferr_ok()?

Keep the warning: something along the lines of "already joined group such and such"

[dwalton76]

We do not display a warning for other commands when they are reconfigured though...this one command is very inconsistent from the rest of the cli experience.