RDMA/cma: Use a helper function to enqueue resolve work items

To avoid errors, with attaching ownership of work item and its cm_id
refcount which is decremented in work handler, tie them up in single
helper function. Also avoid code duplication.

Link: https://lore.kernel.org/r/20200126142652.104803-3-leon@kernel.org


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