minor #10874 Update service_decoration.rst (atailouloute)

This PR was merged into the 3.4 branch.

Discussion
----------

Update service_decoration.rst

Add missing dots

Commits
-------

487ed5c Update service_decoration.rst

Author: javiereguiluz

service_container/service_decoration.rst

@@ -228,12 +228,12 @@ the ``decoration_priority`` option. Its value is an integer that defaults to
         $container->register(Foo:class)
 
         $container->register(Bar:class)
-            ->addArgument(new Reference(Bar:class.'inner'))
+            ->addArgument(new Reference(Bar:class.'.inner'))
             ->setPublic(false)
             ->setDecoratedService(Foo:class, null, 5);
 
         $container->register(Baz:class)
-            ->addArgument(new Reference(Baz:class.'inner'))
+            ->addArgument(new Reference(Baz:class.'.inner'))
             ->setPublic(false)
             ->setDecoratedService(Foo:class, null, 1);