to make goreportcard a bit happier
https://goreportcard.com/report/github.com/docker/docker
also found that `TestCpToErrDstParentNotExists()` was
partially broken, because a `runDockerCp()` was inadvertently
removed in f26a31e80c
`TestDaemonRestartSaveContainerExitCode()` didn't verify
the actual _Error_ message, so added that to the test,
and updated the test to take into account that the
"experimental" CI enables `--init` on containers.
`TestVolumeCLICreateOptionConflict()` only checked
for an error to occur, but didn't validate if the
error was due to conflicting options.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
ba0afd70e8