Remove pointless assert (the node of modes is rather seldom 0 and the pointer...

Remove pointless assert (the node of modes is rather seldom 0 and the pointer has been dereferenced at least thrice before this point).

[r21133]

ir/be/ia32/ia32_transform.c

@@ -2800,7 +2800,6 @@ static ir_node *gen_Cmp(ir_node *node)
 		}
 	}
 	set_am_attributes(new_node, &am);
-	assert(cmp_mode != NULL);
 	set_ia32_ls_mode(new_node, cmp_mode);
 
 	SET_IA32_ORIG_NODE(new_node, ia32_get_old_node_name(env_cg, node));