RDMA/hw/hfi1/user_exp_rcv: Demote half-documented and kernel-doc abuses

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

 drivers/infiniband/hw/hfi1/user_exp_rcv.c:174: warning: Function parameter or member 'fd' not described in 'unpin_rcv_pages'
 drivers/infiniband/hw/hfi1/user_exp_rcv.c:174: warning: Function parameter or member 'tidbuf' not described in 'unpin_rcv_pages'
 drivers/infiniband/hw/hfi1/user_exp_rcv.c:174: warning: Function parameter or member 'node' not described in 'unpin_rcv_pages'
 drivers/infiniband/hw/hfi1/user_exp_rcv.c:174: warning: Function parameter or member 'idx' not described in 'unpin_rcv_pages'
 drivers/infiniband/hw/hfi1/user_exp_rcv.c:174: warning: Function parameter or member 'npages' not described in 'unpin_rcv_pages'
 drivers/infiniband/hw/hfi1/user_exp_rcv.c:174: warning: Function parameter or member 'mapped' not described in 'unpin_rcv_pages'
 drivers/infiniband/hw/hfi1/user_exp_rcv.c:196: warning: Function parameter or member 'fd' not described in 'pin_rcv_pages'
 drivers/infiniband/hw/hfi1/user_exp_rcv.c:196: warning: Function parameter or member 'tidbuf' not described in 'pin_rcv_pages'

Link: https://lore.kernel.org/r/20210126124732.3320971-19-lee.jones@linaro.org


Cc: Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
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>