Refactor: extract greetingPrefix function

hello.go

@@ -11,13 +11,17 @@ func Hello(name string, language string) string {
 		name = "World"
 	}
 
-	prefix := englishHelloPrefix
+	return greetingPrefix(language) + name
+}
+
+func greetingPrefix(language string) (prefix string) {
+	prefix = englishHelloPrefix
 
 	if language == welsh {
 		prefix = welshHelloPrefix
 	}
 
-	return prefix + name
+	return
 }
 
 func main() {