iommu: Restore lost return in iommu_report_device_fault()

In the Linux kernel, the following vulnerability has been resolved: iommu: Restore lost return in iommu_report_device_fault() When iommu_report_device_fault gets called with a partial fault it is supposed to collect the fault into the group and then return. Instead the return was accidently deleted which results in trying to process the fault and an eventual crash. Deleting the return was a typo, put it back.