winex11: Fix handling of bitmap header size for V4/V5 bitmaps.

dlls/winex11.drv/dib.c

@@ -208,7 +208,7 @@ int bitmap_info_size( const BITMAPINFO * info, WORD coloruse )
         if (!colors && (info->bmiHeader.biBitCount <= 8))
             colors = 1 << info->bmiHeader.biBitCount;
         if (info->bmiHeader.biCompression == BI_BITFIELDS) masks = 3;
-        return sizeof(BITMAPINFOHEADER) + masks * sizeof(DWORD) + colors *
+        return info->bmiHeader.biSize + masks * sizeof(DWORD) + colors *
                ((coloruse == DIB_RGB_COLORS) ? sizeof(RGBQUAD) : sizeof(WORD));
     }
 }