Following APIs are not supposed to modify addr or dest_addr contents.
Therefore make those function argument const for better code
readability.

1. rdma_resolve_ip()
2. rdma_addr_size()
3. rdma_resolve_addr()
Signed-off-by: NParav Pandit <parav@mellanox.com>
Reviewed-by: NDaniel Jurgens <danielj@mellanox.com>
Signed-off-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>