coverity#1441102 silence Copy-paste error

Change-Id: I389984fa56a8709416f9d525e4a879993b432bea
Reviewed-on: https://gerrit.libreoffice.org/63077
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

filter/source/graphicfilter/ipict/ipict.cxx

@@ -923,7 +923,7 @@ sal_uLong PictReader::ReadPixMapEtc( BitmapEx &rBitmap, bool bBaseAddr, bool bCo
 
         if (nRowBytes < 8 || nPackType == 1)
         {
-            if (nHeight > pPict->remainingSize() / (sizeof(sal_uInt16) * nWidth))
+            if (nHeight > pPict->remainingSize() / (sizeof(sal_uInt8) * nRowBytes))
                 return 0xffffffff;
         }
         else