Fix copy/pasto in ??? and !!! listops.

Author: pmichaud

lib/operators.pod

@@ -1178,7 +1178,7 @@ statement in a routine or type, it marks that routine or type as a stub
 (which is significant in the context of pre-declaring types and composing
 roles).
 
-If the C<...> statement is executed, it calls L<&die>, with the default
+If the C<!!!> statement is executed, it calls L<&die>, with the default
 message C<stub code executed>.
 
 =head2 listop ???
@@ -1188,7 +1188,7 @@ statement in a routine or type, it marks that routine or type as a stub
 (which is significant in the context of pre-declaring types and composing
 roles).
 
-If the C<...> statement is executed, it calls L<&warn>, with the default
+If the C<???> statement is executed, it calls L<&warn>, with the default
 message C<stub code executed>.
 
 =head1 Loose AND precedence