minor #10699 Wrong function name (MohamedElKadaoui)

This PR was submitted for the 3.4 branch but it was merged into the 2.8 branch instead (closes #10699).

Discussion
----------

Wrong function name

<!--

If your pull request fixes a BUG, use the oldest maintained branch that contains
the bug (see https://symfony.com/roadmap for the list of maintained branches).

If your pull request documents a NEW FEATURE, use the same Symfony branch where
the feature was introduced (and `master` for features of unreleased versions).

-->

Commits
-------

1a940b4 Wrong function name

Author: javiereguiluz

controller/upload_file.rst

@@ -236,7 +236,7 @@ logic to a separate service::
             $fileName = md5(uniqid()).'.'.$file->guessExtension();
 
             try {
-                $file->move($this->getTargetDir(), $fileName);
+                $file->move($this->getTargetDirectory(), $fileName);
             } catch (FileException $e) {
                 // ... handle exception if something happens during file upload
             }