Win32 driver: Fix buffer position calculation in gdisp_lld_blit_area()

Thanks to @nathanwiebe for reporting this.

changelog.txt

@@ -18,6 +18,7 @@ CHANGE:     STM32LTDC driver: Rename GDISP_LTDC_USE_RGB565 to STM32LTDC_USE_RGB5
 FEATURE:    STM32LTDC driver: Support double buffering. This introduces STM32LTDC_USE_DOUBLEBUFFERING.
 FIX:        STM32LTDC driver: Fix bug in gdisp_lld_blit_area() which affected blits with source coordinates other than (0, 0).
 FIX:        Improve /demos/benchmarks/rectangles.
+FIX:        Win32 driver: Fix buffer position calculation in gdisp_lld_blit_area().
 
 
 *** Release 2.9 ***

drivers/multiple/Win32/gdisp_lld_Win32.c

@@ -1283,7 +1283,7 @@ LLDSPEC gBool gdisp_lld_init(GDisplay *g) {
 		// Make everything relative to the start of the line
 		priv = g->priv;
 		buffer = g->p.ptr;
-		buffer += g->p.x2*g->p.y1;
+		buffer += g->p.x2 * g->p.y1 + g->p.x1;
 
 		memset(&bmpInfo, 0, sizeof(bmpInfo));
 		bmpInfo.bV4Size = sizeof(bmpInfo);