Add new flymake-easy--location

Hi, I pull request to add new `flymake-easy--location'

I would like to use `flymake-create-temp-with-folder-structure` function to
create a flymake java checker with flymake-easy.
I think the `flymake-create-temp-with-folder-structure` function is
not problem because `flymake-simple-make-java-init` is already using
this function like this:
```lisp
(defun flymake-simple-make-java-init ()
  (flymake-simple-make-init-impl 'flymake-create-temp-with-folder-structure nil nil "Makefile" 'flymake-get-make-cmdline))
```
Could you merge this pull request?