iommu/tegra: remove invalid reference to list iterator variable

iommu/tegra: remove invalid reference to list iterator variable

If list_for_each_entry, etc complete a traversal of the
list, the iterator variable ends up pointing to an address
at an offset from the list head, and not a meaningful
structure.  Thus this value should not be used after the end
of the iterator.  Replace c->dev by dev, which is the value
that c->dev has been compared to.

This problem was found using Coccinelle (http://coccinelle.lip6.fr/).

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Hiroshi DOYU <hdoyu@nvidia.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>