codedFunctionObject.H: Corrected docs

Resolved bug-report http://bugs.openfoam.org/view.php?id=2313

src/functionObjects/utilities/codedFunctionObject/codedFunctionObject.H

@@ -55,12 +55,11 @@ Description
             // Lookup U
             const volVectorField& U = mesh().lookupObject<volVectorField>("U");
             // Write
-            mag(U).write();
-        }
+            mag(U)().write();
+        #};"
     }
     \endverbatim
 
-
 See also
     Foam::functionObject
     Foam::codedBase