nvme: Don't clear nvme blk device's priv space

A udevice's priv space is cleared in alloc_priv() in the DM core.
Don't do it again in its probe() routine.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c
index d4b2860..f6465ea 100644
--- a/drivers/nvme/nvme.c
+++ b/drivers/nvme/nvme.c
@@ -705,7 +705,6 @@
 	if (!id)
 		return -ENOMEM;
 
-	memset(ns, 0, sizeof(*ns));
 	ns->dev = ndev;
 	/* extract the namespace id from the block device name */
 	ns->ns_id = trailing_strtol(udev->name);