Minor update to generics2 test

tests/generics2.pn

@@ -5,9 +5,8 @@ fn identity(x: int32): int32 {
 }
 
 
+# No call is necessary for the compiler to detect the error:
+# generics are type checked at declaration time!
 fn nope[T: int32 | int16](x: T) {
     return identity(x);
 }
-
-
-nope(5'i16);