iommu/amd: Handle return of iommu_device_sysfs_add

As iommu_device_sysfs_add() can fail, we should check the return value.

Signed-off-by: Bo Liu <liubo03@inspur.com>
Link: https://lore.kernel.org/r/20220701062008.6988-1-liubo03@inspur.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>