metropolis/pkg/efivarfs: use strings.ReplaceAll

Change-Id: Ifb9da5aa20cabc482bbf44cb809b73e32d75e312
Reviewed-on: https://review.monogon.dev/c/monogon/+/3002
Reviewed-by: Serge Bazanski <serge@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/pkg/efivarfs/devicepath.go b/metropolis/pkg/efivarfs/devicepath.go
index 8e9dddb..38dd731 100644
--- a/metropolis/pkg/efivarfs/devicepath.go
+++ b/metropolis/pkg/efivarfs/devicepath.go
@@ -211,7 +211,7 @@
 	if nullIdx != len(out)-1 {
 		return nil, fmt.Errorf("FilePath not properly null-terminated")
 	}
-	withoutBackslashes := strings.Replace(string(out[:len(out)-1]), `\`, `/`, -1)
+	withoutBackslashes := strings.ReplaceAll(string(out[:len(out)-1]), `\`, `/`)
 	return FilePath(withoutBackslashes), nil
 }