Replace all include guard ifdefs with "#pragma once"

Source/Core/Core/HLE/HLE.h

@@ -2,8 +2,7 @@
 // Licensed under GPLv2
 // Refer to the license.txt file included.
 
-#ifndef _HLE_H
-#define _HLE_H
+#pragma once
 
 #include <map>
 #include "CommonTypes.h"
@@ -40,6 +39,3 @@ namespace HLE
 
 	static std::map<u32, u32> orig_instruction;
 }
-
-#endif
-

Source/Core/Core/HLE/HLE_Misc.h

@@ -2,8 +2,7 @@
 // Licensed under GPLv2
 // Refer to the license.txt file included.
 
-#ifndef HLE_MISC_H
-#define HLE_MISC_H
+#pragma once
 
 namespace HLE_Misc
 {
@@ -14,5 +13,3 @@ namespace HLE_Misc
 	void OSGetResetCode();
 	void HLEGeckoCodehandler();
 }
-
-#endif

Source/Core/Core/HLE/HLE_OS.h

@@ -2,8 +2,7 @@
 // Licensed under GPLv2
 // Refer to the license.txt file included.
 
-#ifndef HLE_OS_H
-#define HLE_OS_H
+#pragma once
 
 #include "Common.h"
 
@@ -13,5 +12,3 @@ namespace HLE_OS
 	void HLE_write_console();
 	void HLE_OSPanic();
 }
-
-#endif