video: rk3399_mipi: Combine NULL check into IS_ERR_OR_NULL()

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
1 file changed