- Move from using include guards to pragma once.

- Whilst this is non-standard and potentially makes the code less portable, it's supported by both gcc and msvc and should bringg increased compilation speed due to its optimized behaviour (doesn't need to invoke the preprocessor)
- Patch by Amine Khaldi [amine.khaldi@reactos.org]

svn path=/trunk/; revision=45685

reactos/drivers/network/tcpip/include/tcpdef.h

@@ -14,8 +14,8 @@
  *		as published by the Free Software Foundation; either version
  *		2 of the License, or (at your option) any later version.
  */
-#ifndef _LINUX_TCP_H
-#define _LINUX_TCP_H
+
+#pragma once
 
 #include "linux.h"
 
@@ -183,5 +183,3 @@ struct tcp_info
 	__u32	tcpi_advmss;
 	__u32	tcpi_reordering;
 };
-
-#endif	/* _LINUX_TCP_H */