Avoid explicit cast to smaller sal_uInt16 from larger long

...in what might be an attempt to avoid warnings about signed vs. unsigned
comparisons.  (The mismatch had been there ever since
8ab086b6cc054501bfbf7ef6fa509c393691e860 "initial import".)

Change-Id: I35c849ac5a850cfb2379d7b29e6da6308611c3d7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/87396
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
diff --git a/svtools/source/brwbox/brwbox2.cxx b/svtools/source/brwbox/brwbox2.cxx
index 10a4202..8daede5 100644
--- a/svtools/source/brwbox/brwbox2.cxx
+++ b/svtools/source/brwbox/brwbox2.cxx
@@ -18,6 +18,7 @@
 */

#include <sal/log.hxx>
#include <o3tl/safeint.hxx>
#include <osl/diagnose.h>
#include <tools/debug.hxx>
#include <svtools/brwbox.hxx>
@@ -1359,7 +1360,7 @@ void BrowseBox::MouseMove( const MouseEvent& rEvt )
    sal_uInt16 nX = 0;
    for ( size_t nCol = 0;
          nCol < mvCols.size() &&
            ( nX + mvCols[ nCol ]->Width() ) < sal_uInt16(GetOutputSizePixel().Width());
            ( nX + mvCols[ nCol ]->Width() ) < o3tl::make_unsigned(GetOutputSizePixel().Width());
          ++nCol )
        // is this column visible?
        if ( mvCols[ nCol ]->IsFrozen() || nCol >= nFirstCol )