test: don't use wiki urls for documentation comments

Also make consistent use of \ as documentation escape character.

test/testautomation_joystick.c

@@ -11,9 +11,9 @@
 /* Test case functions */
 
 /**
- * @brief Check virtual joystick creation
+ * \brief Check virtual joystick creation
  *
- * @sa SDL_AttachVirtualJoystickEx
+ * \sa SDL_AttachVirtualJoystickEx
  */
 static int
 TestVirtualJoystick(void *arg)