[AD] minor bug in src/graphics.c

[Edgar <edgarreynaldo@xxxxxxxxxx>]

In src/graphics.c on lines 1413 and 1414 allegro 4.4.1.1 falls back to 
creating a memory bitmap if it cannot create a system bitmap, but it 
incorrectly alters the id of the bitmap to add the BMP_ID_SYSTEM flag 
even though it is only a memory bitmap. I made a patch to remove this 
line that is attached. I can't see why the bitmap should be identified 
as a system bitmap if it is not, even if create_system_bitmap created it 
(by calling create_bitmap).


--- graphics_old.c	2011-03-08 22:59:03.434938000 -0600
+++ graphics.c	2011-04-28 03:01:19.166519500 -0500
@@ -1411,7 +1411,6 @@
       return gfx_driver->create_system_bitmap(width, height);
 
    bmp = create_bitmap(width, height);
-   bmp->id |= BMP_ID_SYSTEM;
 
    return bmp;
 }