media: v4l: subdev: Fail graciously when getting try data for NULL state

media: v4l: subdev: Fail graciously when getting try data for NULL state

[ Upstream commit 2ba3e38517f5a4ebf9c997168079dca01b7f9fc6 ]

The state argument for the functions for obtaining various parts of the
state is NULL if it is called by drivers for active state. Fail graciously
in that case instead of dereferencing a NULL pointer.

Suggested-by: Bingbu Cao <bingbu.cao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>