Rework this param

example/src/main.nub

@@ -1,12 +1,12 @@
-extern func puts(fmt: cstring)
+extern func puts(text: cstring)
 
 struct Human
 {
     name: cstring
 
-    func str(): cstring
+    func print()
     {
-        return this.name
+        puts(this.name)
     }
 }
 
@@ -16,7 +16,7 @@ func main(args: []cstring): i64
         name = "oliver"
     }
 
-    puts(human.str())
+    human.print()
 
     return 0
 }