Fixed a copy-paste error in QRasterPixmapData::metric().
Fixed a copy-paste error in QRasterPixmapData::metric().

Calling metric() to get the device height in mm of a pixmap when using
the raster engine would actually return the width..

Task-number: QTBUG-6985
Reviewed-by: Carlos Duclos
(cherry picked from commit 4bd7e6930fcd9e04696aa5426691cd90ba383a32)

pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk