PCI: mobiveil: Simplify mobiveil_pcie_init_irq_domain() return expression

Simplify the return expression by removing useless code.

Link: https://lore.kernel.org/r/20200921082447.2591877-1-liushixin2@huawei.com


Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>