RDMA/cxgb3: Endianness annotation for irs field

t3_rdma_init_wr.irs is a big-endian field, so declare it as __be32.
This fixes one sparse warning.
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/cxgb3/cxio_wr.h

@@ -315,7 +315,7 @@ struct t3_rdma_init_wr {
 	__be32 ird;
 	__be64 qp_dma_addr;	/* 7 */
 	__be32 qp_dma_size;	/* 8 */
-	u32 irs;
+	__be32 irs;
 };
 
 struct t3_genbit {