minor symfony#7260 [Workflow] Add missing semicolon to workflow usage code block (dominikhajduk)

This PR was merged into the 3.2 branch.

Discussion
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[Workflow] Add missing semicolon to workflow usage code block

Fix second code block example on: http://symfony.com/doc/current/workflow/usage.html
```
class BlogPost
{
    // This property is used by the marking store
    public $currentPlace;
    public $title;
    public $content     // missing ;
}
```

Commits
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96538b9 Fix typo in workflow usage code lock

Author: xabbuh

workflow/usage.rst

@@ -140,7 +140,7 @@ like this:
         // This property is used by the marking store
         public $currentPlace;
         public $title;
-        public $content
+        public $content;
     }
 
 .. note::