IB/core: Namespace is mandatory input for address resolution

In function addr_resolve() the namespace is a required input parameter
and not an output. It is passed later for searching the routing table
and device addresses. Also, it shouldn't be copied back to the caller.

Fixes: 565edd1d ('IB/addr: Pass network namespace as a parameter')
Cc: <stable@vger.kernel.org> # v4.3+
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>