IB/srp: Fix indirect data buffer rkey endianness

Detected by sparse.

Fixes: commit 330179f2 ("IB/srp: Register the indirect data buffer descriptor")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: stable <stable@vger.kernel.org> # v4.3+
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/srp/ib_srp.c

@@ -1662,7 +1662,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
 			return ret;
 		req->nmdesc++;
 	} else {
-		idb_rkey = target->global_mr->rkey;
+		idb_rkey = cpu_to_be32(target->global_mr->rkey);
 	}
 
 	indirect_hdr->table_desc.va = cpu_to_be64(req->indirect_dma_addr);