On IOMMU systems DMA mapping can fail, we need to check for
that possibility.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit 10545937)
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>