internal/rosa/package: migrate remaining trivial packages

The rest are migrated individually.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/main.go

@@ -91,6 +91,10 @@ func main() {
 		addr net.UnixAddr
 	)
 	c := command.New(os.Stderr, log.Printf, "mbf", func([]string) error {
+		if !rosa.Native().HasStage0() {
+			return pkg.UnsupportedArchError(runtime.GOARCH)
+		}
+
 		if flagPT {
 			log.Println("parsed in", rosa.ParseTime())
 		}
@@ -127,7 +131,7 @@ func main() {
 			}
 
 			rosa.Native().DropCaches(flagArch, flags)
-			if !rosa.HasStage0() {
+			if !rosa.Native().HasStage0() {
 				return pkg.UnsupportedArchError(flagArch)
 			}
 		}