ssh: return authErr array if all authentication attempts fail

Change-Id: I4d6cab266410a8c7960073665eddf8935693087f
Reviewed-on: https://go-review.googlesource.com/44332
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2 files changed