Fix doxygen warning

Author: nyalldawson

python/core/auto_generated/dxf/qgsdxfexport.sip.in

@@ -401,7 +401,7 @@ Write mtext (MTEXT)
 %Docstring
 Returns scale factor for conversion to map units
 
-:param scaleDenominator: the map scale denominator
+:param scale: the map scale denominator
 :param symbolUnits: the symbol output units
 :param mapUnits: the map units
 :param mapUnitsPerPixel: Map units per pixel

src/core/dxf/qgsdxfexport.h

@@ -386,7 +386,7 @@ class CORE_EXPORT QgsDxfExport
 
     /**
      * Returns scale factor for conversion to map units
-     * \param scaleDenominator the map scale denominator
+     * \param scale the map scale denominator
      * \param symbolUnits the symbol output units
      * \param mapUnits the map units
      * \param mapUnitsPerPixel Map units per pixel