ocxl: simplify the return expression of free_function_dev()

Simplify the return expression.

Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Link: https://lore.kernel.org/r/20200921131047.92526-1-miaoqinglang@huawei.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>