iommu/rockchip: Checking a device_link_add() call in rk_iommu_add_device()

[Markus Elfring]

Hello,

I tried another script for the semantic patch language out.
This source code analysis approach points out that the implementation
of the function ârk_iommu_add_deviceâ contains still
an unchecked call of the function âdevice_link_addâ.
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/iommu/rockchip-iommu.c?id=3ef845da3c3b180ddd386e228ac3228d84a522d3#n1075
https://elixir.bootlin.com/linux/v5.4-rc2/source/drivers/iommu/rockchip-iommu.c#L1071

How do you think about to improve it?

Which error code would you like to return for a failed
device link addition at this place?

Regards,
Markus