IB/user_mad: Fix buggy usage of port index

The addition of the rdma_cap_ib_mad is technically broken in ib_umad_remove_one
because the loop "i" value is not a port value.

This bug resulted in the ib_umad failing to properly remove its resources when
the core capability functions were converted to bit fields.

NOTE: e17371d73908 did not result in broken behavior on its own.  It was only
an issue when the implementation of rdma_cap_ib_mad was changed.

Pass the port value to rdma_cap_ib_mad.

Fixes: e17371d73908 ("IB/Verbs: Use management helper rdma_cap_ib_mad()")
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/infiniband/core/user_mad.c

@@ -1325,7 +1325,7 @@ static void ib_umad_remove_one(struct ib_device *device)
 		return;
 
 	for (i = 0; i <= rdma_end_port(device) - rdma_start_port(device); ++i) {
-		if (rdma_cap_ib_mad(device, i))
+		if (rdma_cap_ib_mad(device, i + rdma_start_port(device)))
 			ib_umad_kill_port(&umad_dev->port[i]);
 	}