RDMA/providers: Remove pointless functions

The rdma core is taking care of return the right error code when the
rdma device callbacks aren't supported.

Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/ocrdma/ocrdma_ah.h

@@ -55,7 +55,6 @@ struct ib_ah *ocrdma_create_ah(struct ib_pd *pd, struct rdma_ah_attr *ah_attr,
 			       struct ib_udata *udata);
 int ocrdma_destroy_ah(struct ib_ah *ah);
 int ocrdma_query_ah(struct ib_ah *ah, struct rdma_ah_attr *ah_attr);
-int ocrdma_modify_ah(struct ib_ah *ah, struct rdma_ah_attr *ah_attr);
 
 int ocrdma_process_mad(struct ib_device *,
 		       int process_mad_flags,