IB/srp: Use pd->local_dma_lkey

Replace all leys with pd->local_dma_lkey. This driver does not support
iWarp, so this is safe.

The insecure use of ib_get_dma_mr is thus isolated to an rkey, and will
have to be fixed separately.

Signed-off-by: Jason Gunthorpe <[e-mail]>
Reviewed-by: Sagi Grimberg <[e-mail]>
Reviewed-by: Bart Van Assche <[e-mail]>
Signed-off-by: Doug Ledford <[e-mail]>

drivers/infiniband/ulp/srp/ib_srp.c

···
 	target->io_class	= SRP_REV16A_IB_IO_CLASS;
 	target->scsi_host	= target_host;
 	target->srp_host	= host;
-	target->lkey		= host->srp_dev->mr->lkey;
+	target->lkey		= host->srp_dev->pd->local_dma_lkey;
 	target->rkey		= host->srp_dev->mr->rkey;
 	target->cmd_sg_cnt	= cmd_sg_entries;
 	target->sg_tablesize	= indirect_sg_entries ? : cmd_sg_entries;