minor symfony#12966 [Workflow] Fix invalid variable name (piotrantosik)

This PR was merged into the 4.3 branch.

Discussion
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[Workflow] Fix invalid variable name

Commits
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4ac71d1 Fix invalid variable name

Author: javiereguiluz

workflow.rst

@@ -240,7 +240,7 @@ registry in the constructor::
 
             // Update the currentState on the post
             try {
-                $workflow->apply($post, 'to_review');
+                $workflow->apply($blogPost, 'to_review');
             } catch (LogicException $exception) {
                 // ...
             }