infiniband: fix ulp/opa_vnic/opa_vnic_vema.c kernel-doc notation

Use correct parameter name and description in kernel-doc notation to
eliminate a kernel-doc warning.

../drivers/infiniband/ulp/opa_vnic/opa_vnic_vema.c:730: warning: Excess function parameter 'cport' description in 'opa_vnic_vema_send_trap'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: linux-doc@vger.kernel.org
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>