Use pragma once instead of header guard

This is a test on a random file to see if all compilers accept this.

Change-Id: I412aef57730d07c8e6e2710fee71d5eded326d48
Reviewed-on: https://gerrit.libreoffice.org/68896
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

sw/source/core/text/itrpaint.hxx

@@ -16,8 +16,9 @@
  *   except in compliance with the License. You may obtain a copy of
  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  */
-#ifndef INCLUDED_SW_SOURCE_CORE_TEXT_ITRPAINT_HXX
-#define INCLUDED_SW_SOURCE_CORE_TEXT_ITRPAINT_HXX
+
+#pragma once
+
 #include "itrtxt.hxx"
 
 class SwSaveClip;          // SwTextPainter
@@ -61,6 +62,4 @@ public:
 
 bool IsUnderlineBreak( const SwLinePortion& rPor, const SwFont& rFnt );
 
-#endif
-
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */