drm/gem: handlecount isn't really a kref so don't make it one.

There were lots of places being inconsistent since handle count
looked like a kref but it really wasn't.

Fix this my just making handle count an atomic on the object,
and have it increase the normal object kref.

Now i915/radeon/nouveau drivers can drop the normal reference on
userspace object creation, and have the handle hold it.

This patch fixes a memory leak or corruption on unload, because
the driver had no way of knowing if a handle had been actually
added for this object, and the fbcon object needed to know this
to clean itself up properly.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 7bdc962..56ad9df 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -237,8 +237,10 @@
 	drm_fb_helper_fini(&ifbdev->helper);
 
 	drm_framebuffer_cleanup(&ifb->base);
-	if (ifb->obj)
+	if (ifb->obj) {
+		drm_gem_object_handle_unreference(ifb->obj);
 		drm_gem_object_unreference(ifb->obj);
+	}
 
 	return 0;
 }