MdeModulePkg/Ip4Dxe: Refine the coding style.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1180
Remove the trailing white spaces.

Cc: Ye Ting <ting.ye@intel.com>
Cc: Fu Siyuan <siyuan.fu@intel.com>
Cc: Bi Dandan <dandan.bi@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Wu Jiaxin <jiaxin.wu@intel.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Dandan Bi <dandan.bi@intel.com>

MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Impl.c

@@ -675,9 +675,9 @@ Ip4ConfigProtocol (
     // Add a route to this connected network in the instance route table.
     //
     Ip4AddRoute (
-      IpInstance->RouteTable, 
-      Ip & Netmask, 
-      Netmask, 
+      IpInstance->RouteTable,
+      Ip & Netmask,
+      Netmask,
       IP4_ALLZERO_ADDRESS
       );
   } else {