IB/mlx5: Make coding style more consistent

These three related functions can't agree whether to put the
umrwr on the stack dirty and then memset it, or to initialize
it on the stack.  Make them all agree.

Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index dd92314..628f4350 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -860,7 +860,7 @@
 	struct device *ddev = dev->ib_dev.dma_device;
 	struct umr_common *umrc = &dev->umrc;
 	struct mlx5_ib_umr_context umr_context;
-	struct mlx5_umr_wr umrwr;
+	struct mlx5_umr_wr umrwr = {};
 	struct ib_send_wr *bad;
 	struct mlx5_ib_mr *mr;
 	struct ib_sge sg;
@@ -892,7 +892,6 @@
 
 	mlx5_ib_init_umr_context(&umr_context);
 
-	memset(&umrwr, 0, sizeof(umrwr));
 	umrwr.wr.wr_cqe = &umr_context.cqe;
 	prep_umr_reg_wqe(pd, &umrwr.wr, &sg, dma, npages, mr->mmkey.key,
 			 page_shift, virt_addr, len, access_flags);
@@ -1196,13 +1195,12 @@
 {
 	struct umr_common *umrc = &dev->umrc;
 	struct mlx5_ib_umr_context umr_context;
-	struct mlx5_umr_wr umrwr;
+	struct mlx5_umr_wr umrwr = {};
 	struct ib_send_wr *bad;
 	int err;
 
 	mlx5_ib_init_umr_context(&umr_context);
 
-	memset(&umrwr.wr, 0, sizeof(umrwr));
 	umrwr.wr.wr_cqe = &umr_context.cqe;
 	prep_umr_unreg_wqe(dev, &umrwr.wr, mr->mmkey.key);