Fix comments priority (single_line_comment_style)

[mvorisek]

Bug report

version: 2.17.2

Code snippet that reproduces the problem

function x()
{
-        return /* what to put here? */;
+        /* what to put here? */
}

needs one more run to stabilize:

-        /* what to put here? */
+        // what to put here?

thus I belive single_line_comment_style rule should be applied later than no_useless_return.