Summary:
Socket errors are handled in libdbus conditionally. There was no need to set an error
on any kind of error code.
This caused libdbus to drop our P2P connection, since MacOS regularly raised
EAGAIN warning on the socket which seems to be expected behavior.
Reviewers: #gatekeepers
Maniphest Tasks: T513
Differential Revision: https://dev.swift-project.org/D95