RDMA/siw: Fix setting active_mtu attribute

Make sure to set the active_mtu attribute to avoid report the following
invalid value:

$ ibv_devinfo -d siw0 | grep active_mtu
			active_mtu:		invalid MTU (0)

Fixes: 303ae1cd ("rdma/siw: application interface")
Link: https://lore.kernel.org/r/20200205081354.30438-1-kamalheib1@gmail.comSigned-off-by: Kamal Heib <kamalheib1@gmail.com>
Reviewed-by: Gal Pressman <galpress@amazon.com>
Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/sw/siw/siw_verbs.c

@@ -168,12 +168,12 @@ int siw_query_port(struct ib_device *base_dev, u8 port,
 
 	memset(attr, 0, sizeof(*attr));
 
-	attr->active_mtu = attr->max_mtu;
 	attr->active_speed = 2;
 	attr->active_width = 2;
 	attr->gid_tbl_len = 1;
 	attr->max_msg_sz = -1;
 	attr->max_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
+	attr->active_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
 	attr->phys_state = sdev->state == IB_PORT_ACTIVE ?
 		IB_PORT_PHYS_STATE_LINK_UP : IB_PORT_PHYS_STATE_DISABLED;
 	attr->pkey_tbl_len = 1;