RDMA/hw/qib/qib_qp: Fix some issues in worthy kernel-doc headers and demote another

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

 drivers/infiniband/hw/qib/qib_qp.c:214: warning: Function parameter or member 'rdi' not described in 'qib_free_all_qps'
 drivers/infiniband/hw/qib/qib_qp.c:387: warning: Function parameter or member 'qp' not described in 'qib_check_send_wqe'
 drivers/infiniband/hw/qib/qib_qp.c:387: warning: Function parameter or member 'wqe' not described in 'qib_check_send_wqe'
 drivers/infiniband/hw/qib/qib_qp.c:387: warning: Function parameter or member 'call_send' not described in 'qib_check_send_wqe'
 drivers/infiniband/hw/qib/qib_qp.c:425: warning: Function parameter or member 's' not described in 'qib_qp_iter_print'
 drivers/infiniband/hw/qib/qib_qp.c:425: warning: Function parameter or member 'iter' not described in 'qib_qp_iter_print'

Link: https://lore.kernel.org/r/20210121094519.2044049-13-lee.jones@linaro.org
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Mike Marciniszyn <mike.marciniszyn@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>