Fix memory leak in openssh

[emaste]

Summary

packet.c ssh_packet_read_seqnr
Change the error handling of SSH_ERR_CON_TIMEOUT to be consistent with the other error handling. This fixes a memory leak with setp.

Test Plan

Run clang's static analyzer, scan-build, before to reproduce the problem, run scan-build after to show the problem is resolved.

[• lidl]

I forwarded this diff to 'des' (who doesn't use phabricator).

His suggestion that this bug ought to be forwarded upstream, to
the openssh maintainers, and we can pickup the fix from them.

(No debate that there's a memory leak, just a different manner of
getting the fix into FreeBSD.)

[trix_juniper.net]

Ok, i will get this upstreamed.

[delphij]

Add maintainer. (I think this should be upstreamed?)

[trix_juniper.net]

I have submitted bug reports to openssh here
https://bugzilla.mindrot.org/show_bug.cgi?id=2683
https://bugzilla.mindrot.org/show_bug.cgi?id=2684

[emaste]

https://bugzilla.mindrot.org/show_bug.cgi?id=2683

that's this change, now fixed upstream; this review can be closed

https://bugzilla.mindrot.org/show_bug.cgi?id=2684

CLOSED WONTFIX