editeng: Don’t unintentionally set KernArray.mnSubUnitFactor

The first (and only) argument to KernArray constructor is nSubUnitFactor
not array length as the code here seems to imply.

Change-Id: Ie89c41d07f1aa13be595ead604df82ad775df433
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/154799
Tested-by: Jenkins
Reviewed-by: خالد حسني <khaled@libreoffice.org>

editeng/source/items/svxfont.cxx

@@ -441,7 +441,7 @@ Size SvxFont::GetPhysTxtSize( const OutputDevice *pOut, const OUString &rTxt,
     if( IsFixKerning() && ( nLen > 1 ) )
     {
         auto nKern = GetFixKerning();
-        KernArray aDXArray(nLen);
+        KernArray aDXArray;
         GetTextArray(pOut, rTxt, &aDXArray, nIdx, nLen);
         tools::Long nOldValue = aDXArray[0];
         sal_Int32 nSpaceCount = 0;