Change "'<" and "'>" to "v" and ".".

`'<` and `'>` are mark of the last selected visual area in the current buffer,
so, search pattern at the first time in the current buffer is different from pattern at the second time.

* first time
  ```
vim ./plugin/asterisk.vim
:map * <Plug>(asterisk-z*)
/save_cpo
zo
fc
v2l
*
``` 

 * search pattern is `\V\<cpo\>`

* second time
  ```
Fc
v2l
*
```
 * search pattern is `\Vcpo\>`