RDMA/core/restrack: Fix kernel-doc formatting issue

RDMA/core/restrack: Fix kernel-doc formatting issue

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

 drivers/infiniband/core/restrack.c:209: warning: Function parameter or member 'res' not described in 'rdma_restrack_new'
 drivers/infiniband/core/restrack.c:209: warning: Function parameter or member 'type' not described in 'rdma_restrack_new'

Link: https://lore.kernel.org/r/20210118223929.512175-17-lee.jones@linaro.org
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>