`go test` complains about this tree because the package ends up with no
symbols on non-Linux platforms, e.g., Windows, even though this API is
never be called on non-Linux platforms, according to the compiler.
Signed-off-by: Paul "TBBle" Hampson <Paul.Hampson@Pobox.com>
```
[5/5] RUN --mount=target=/go/src/github.com/moby/buildkit gometalinter ...
0.435 util/rootless/specconv/specconv_linux.go:1:⚠️ file is not goimported (goimports)
1.320 cache/manager.go:1:⚠️ file is not goimported (goimports)
1.335 cache/manager_test.go:1:⚠️ file is not goimported (goimports)
1.337 cache/migrate_v2.go:1:⚠️ file is not goimported (goimports)
1.342 cache/refs.go:1:⚠️ file is not goimported (goimports)
1.454 cache/remotecache/registry/registry.go:1:⚠️ file is not goimported (goimports)
2.285 cmd/buildctl/build.go:1:⚠️ file is not goimported (goimports)
3.082 executor/oci/user.go:1:⚠️ file is not goimported (goimports)
4.333 session/content/content_test.go:1:⚠️ file is not goimported (goimports)
4.614 snapshot/containerd/content.go:1:⚠️ file is not goimported (goimports)
4.721 solver/errdefs/vertex.go:1:⚠️ file is not goimported (goimports)
6.066 util/network/cniprovider/cni.go:1:⚠️ file is not goimported (goimports)
ERROR: executor failed running [/bin/sh -c gometalinter --config=gometalinter.json ./...]: buildkit-runc did not terminate successfully
```
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
CrazyMax
Paul "TBBle" Hampson
Sebastiaan van Stijn
Akihiro Suda
Noel Georgi