RDMA/{cma, core}: Avoid callback on rdma_addr_cancel()

Currently rdma_addr_cancel() is an async operation, which notifies that
cancel is done by executing the callback function given during
rdma_resolve_ip(). If resolve_ip request is already completed than
callback is not executed.

Instead, now rdma_resolve_addr() and rdma_addr_cancel() simplified in
following ways.
1. rdma_addr_cancel() now a synchronous method. If request was
pending, after it is cancelled, no callback is notified.
2. rdma_resolve_addr() and respective addr_handler() callback doesn't
need to hold reference to cm_id.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>