Address infinite loop when recursively resolving routes.

[robshakir]

* (M) sysrib/{server,server_test,sysrib,sysrib_test}.go
   - Avoid infinite stack depth when a route recurses onto itself.
     Previously, looking up a next-hop or next-hop interface would
     not track the visited nodes, and hence infinite recursion could
     occur. This PR adds tracking of these changes into the RIB
     lookup to avoid this.

[github-actions[bot]]

Pull Request Test Coverage Report for Build 10175027886

Details

• 29 of 29 (100.0%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.004%) to 2.858%

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Files with Coverage Reduction	New Missed Lines	%
sysrib/static.go	1	90.41%
<!--	Total:	1		-->

Totals
Change from base Build 10101306638:	0.004%
Covered Lines:	18825
Relevant Lines:	658631

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💛 - Coveralls