[media] rc: ite-cir: fix potential double free in ite_probe()

Since rc_unregister_device() frees its argument, the subsequently
call to rc_free_device() on the same variable will cause a double
free bug. Fix by set argument to NULL, thus when fall through to
rc_free_device(), nothing will be done there.

Signed-off-by: Wei Yongjun <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/rc/ite-cir.c

···
 	release_region(itdev->cir_addr, itdev->params.io_region_size);
 exit_unregister_device:
 	rc_unregister_device(rdev);
+	rdev = NULL;
 exit_free_dev_rdev:
 	rc_free_device(rdev);
 	kfree(itdev);