gma500: introduce the framebuffer support code

[Dan Carpenter]

Hello Alan Cox,

The patch 4d8d096e9ae8: "gma500: introduce the framebuffer support
code" from Nov 3, 2011, leads to the following static checker warning:

	drivers/gpu/drm/gma500/framebuffer.c:488 psbfb_create()
	warning: passing freed memory 'backing'

drivers/gpu/drm/gma500/framebuffer.c
   481  out_unref:
   482          if (backing->stolen)
   483                  psb_gtt_free_range(dev, backing);
                                                ^^^^^^^
This function always frees backing.

   484          else
   485                  drm_gem_object_unreference(&backing->gem);
   486  out_err1:
   487          mutex_unlock(&dev->struct_mutex);
   488          psb_gtt_free_range(dev, backing);
                                        ^^^^^^^
Double free.

   489          return ret;
   490  }

regards,
dan carpenter