Merge branch 'iommu-common-fixes'

Sowmini Varadhan says:

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iommu-common build warning fixes.

This patchset has fixes for 2 architectures
- Part 1: x86_64 warnings generated by sparse
- Part 2: allmodconfig build error for powerpc, identified by Guenter Roeck.
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Signed-off-by: David S. Miller <davem@davemloft.net>