staging: greybus: fix a missing-check bug in gb_lights_light_config()

staging: greybus: fix a missing-check bug in gb_lights_light_config()

[ Upstream commit 9bb086e5ba9495ac150fbbcc5c8c2bccc06261dd ]

In gb_lights_light_config(), 'light->name' is allocated by kstrndup().
It returns NULL when fails, add check for it.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Link: https://lore.kernel.org/r/20200401030017.100274-1-chenzhou10@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>