osbuild/mkdir: rename Path struct to MkdirStagePath

The plain `Path` name was a bit unfortunate, since it was specific to
the `mkdir` stage, but it was used outside of the `osbuild` package as
`osbuild.Path` which was making a wrong impression of it being a generic
path structure. This is not true.

Rename the structure to contain the stage name.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

internal/osbuild/mkdir_stage.go

@@ -4,10 +4,10 @@ import "os"
 
 // Options for the org.osbuild.ostree.config stage.
 type MkdirStageOptions struct {
-	Paths []Path `json:"paths"`
+	Paths []MkdirStagePath `json:"paths"`
 }
 
-type Path struct {
+type MkdirStagePath struct {
 	Path string `json:"path"`
 
 	Mode os.FileMode `json:"mode,omitempty"`