validation: print out correct diagnostics based on specError
validation: print out correct diagnostics based on specError

Like other tests, `testNamespacePath` should also print out details
about the failed tests, based on specError.
Also make `waitForState(doCheckNamespacePath)` return a correct error
coming from `checkNamespacePath`, not from `waitForState`.

Signed-off-by: Dongsu Park <696fb7639d678a1e692fa501217d7509545d7331@kinvolk.io>

opencontainers/ocitools,opencontainers/runtime-tools,opencontainers/runtime-tools,opencontainers/ocitools