Platform: Fix error path in samsung-laptop init

samsung_init() should not return success if not all devices are initialized.
Otherwise, samsung_exit() will dereference sdev NULL pointers and others.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Matthew Garrett <mjg@redhat.com>