RDMA/core: device: Fix formatting in worthy kernel-doc header and demote another

RDMA/core: device: Fix formatting in worthy kernel-doc header and demote another

Fixes the following W=1 kernel build warning(s):

 drivers/infiniband/core/device.c:1896: warning: Function parameter or member 'ibdev' not described in 'ib_get_client_nl_info'
 drivers/infiniband/core/device.c:1896: warning: Function parameter or member 'client_name' not described in 'ib_get_client_nl_info'
 drivers/infiniband/core/device.c:1896: warning: Function parameter or member 'res' not described in 'ib_get_client_nl_info'
 drivers/infiniband/core/device.c:2328: warning: Function parameter or member 'nldev_cb' not described in 'ib_enum_all_devs'
 drivers/infiniband/core/device.c:2328: warning: Function parameter or member 'skb' not described in 'ib_enum_all_devs'

Link: https://lore.kernel.org/r/20210118223929.512175-3-lee.jones@linaro.org
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>