cppcanvas: processEMFPlus: fix valgrind warning:

When reading EmfPlusRecordTypeDrawImagePoints, handle the variant where
points are stored as 16-bit integers instead of floats correctly.
Found via valgrind on loading bugdoc from fdo#42252.

cppcanvas/source/inc/implrenderer.hxx

@@ -215,7 +215,7 @@ static float GetSwapFloat( SvStream& rSt )
 
             /* EMF+ */
             void ReadRectangle (SvStream& s, float& x, float& y, float &width, float& height, sal_uInt32 flags = 0);
-            void ReadPoint (SvStream& s, float& x, float& y, sal_uInt32 flags = 0);
+            void ReadPoint (SvStream& s, float& x, float& y, sal_uInt32 flags);
             void MapToDevice (double &x, double &y);
             ::basegfx::B2DPoint Map (double ix, double iy);
             ::basegfx::B2DSize MapSize (double iwidth, double iheight);

cppcanvas/source/mtfrenderer/emfplus.cxx

@@ -1406,9 +1406,9 @@ namespace cppcanvas
                             if (unknown == 3) { // it probably means number of points defining destination rectangle
                                 float x1, y1, x2, y2, x3, y3;
 
-                                ReadPoint (rMF, x1, y1);
-                                ReadPoint (rMF, x2, y2);
-                                ReadPoint (rMF, x3, y3);
+                                ReadPoint (rMF, x1, y1, flags);
+                                ReadPoint (rMF, x2, y2, flags);
+                                ReadPoint (rMF, x3, y3, flags);
 
                                 BitmapEx aBmp( image.graphic.GetBitmapEx () );
                                 const Rectangle aCropRect (::vcl::unotools::pointFromB2DPoint (Map (sx, sy)),