`nm-online --wait-for-startup` isn't really intended to be called directly.
It is mainly for implementing "NetworkManager-wait-online.service".

Anyway, at the end, the result does not indicate the connectivty status
of the host. Hence, printing

  Connecting...............   30s [online]

is misleading. It merely means, that startup is complete. Likewise,
printing "[offline]" would not mean that there is no connectivity.
Instead, it means that startup is still in progress on timeout.

As it is now, the distinction between whether to print "start-pending"
and "failure" is not very clear. Not that it matters much. At least is
corresponds to the exit status of the program. If we sometimes confuse
EXIT_FAILURE_OFFLINE with other failure reasons, the exit status needs
to be corrected first.

https://github.com/NetworkManager/NetworkManager/pull/152