cmd/tailscaled, tsnet: don't return an interface containing a nil pointer

This tripped me up when I was testing something and wrote:

    if conn != nil {
        conn.Close()
    }

In netstack mode, when an error occurred we were getting a non-nil error
and a non-nil interface that contained a nil pointer. Instead, just
return a nil interface value.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id9ef3dd24529e0e8c53adc60ed914c31fbb10cc4

0 files changed, 0 insertions, 0 deletions