Annotate ENET init #endif comment

Adds an inline `// AvV` comment to the `#endif` in `enet_init` to clarify the conditional block boundary without changing behavior.

Author: vanvught

lib-gd32/gd32f10x/GD32F10x_standard_peripheral/Source/gd32f10x_enet.c

@@ -331,7 +331,7 @@ ErrStatus enet_init(enet_mediamode_enum mediamode, enet_chksumconf_enum checksum
             return enet_state;
         }  
     }
-#endif
+#endif // AvV
     /* initialize ENET peripheral with generally concerned parameters */
     enet_default_init();