address a few nits

Docker-DCO-1.1-Signed-off-by: Tibor Vass <teabee89@gmail.com> (github: tiborvass)
Fix io.Reader ambiguity on EOF in progressreader

Docker-DCO-1.1-Signed-off-by: Tibor Vass <teabee89@gmail.com> (github: tiborvass)
Merge pull request #7251 from tiborvass/fix-test-import-display

Fix test import display