Update calls.rst

Elsewhere in the documentation, the syntax used is `- [method, arguments array]`.

Author: Dominic-Mayers

service_container/calls.rst

@@ -40,7 +40,7 @@ To configure the container to call the ``setLogger`` method, use the ``calls`` k
             App\Service\MessageGenerator:
                 # ...
                 calls:
-                    - setLogger: ['@logger']
+                    - [setLogger, ['@logger']]
 
     .. code-block:: xml