Add unconvert linter and apply fixes

Signed-off-by: Sascha Grunert <sgrunert@suse.com>

.golangci.yml

@@ -23,6 +23,7 @@ linters:
     - staticcheck
     - structcheck
     - typecheck
+    - unconvert
     - unparam
     - unused
     - varcheck
@@ -41,4 +42,3 @@ linters:
     # - prealloc
     # - scopelint
     # - stylecheck
-    # - unconvert

chroot/run.go

@@ -569,7 +569,7 @@ func runUsingChroot(spec *specs.Spec, bundlePath string, ctty *os.File, stdin io
 	cmd.UnshareFlags = syscall.CLONE_NEWUTS | syscall.CLONE_NEWNS
 	requestedUserNS := false
 	for _, ns := range spec.Linux.Namespaces {
-		if ns.Type == specs.LinuxNamespaceType(specs.UserNamespace) {
+		if ns.Type == specs.UserNamespace {
 			requestedUserNS = true
 		}
 	}

commit.go

@@ -184,8 +184,8 @@ func (b *Builder) Commit(ctx context.Context, dest types.ImageReference, options
 	}
 	// In case we're using caching, decide how to handle compression for a cache.
 	// If we're using blob caching, set it up for the source.
-	var maybeCachedSrc = types.ImageReference(src)
-	var maybeCachedDest = types.ImageReference(dest)
+	maybeCachedSrc := src
+	maybeCachedDest := dest
 	if options.BlobDirectory != "" {
 		compress := types.PreserveOriginal
 		if options.Compression != archive.Uncompressed {
@@ -301,7 +301,7 @@ func Push(ctx context.Context, image string, dest types.ImageReference, options
 	if err != nil {
 		return nil, "", err
 	}
-	var maybeCachedSrc = types.ImageReference(src)
+	maybeCachedSrc := src
 	if options.BlobDirectory != "" {
 		compress := types.PreserveOriginal
 		if options.Compression != archive.Uncompressed {