Btrfs: fix some endian bugs handling the root times

"trans->transid" is cpu endian but we want to store the data as little
endian.  "item->ctime.nsec" is only 32 bits, not 64.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 43f0012..a1fbca0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -424,7 +424,7 @@
 	uuid_le_gen(&new_uuid);
 	memcpy(root_item.uuid, new_uuid.b, BTRFS_UUID_SIZE);
 	root_item.otime.sec = cpu_to_le64(cur_time.tv_sec);
-	root_item.otime.nsec = cpu_to_le64(cur_time.tv_nsec);
+	root_item.otime.nsec = cpu_to_le32(cur_time.tv_nsec);
 	root_item.ctime = root_item.otime;
 	btrfs_set_root_ctransid(&root_item, trans->transid);
 	btrfs_set_root_otransid(&root_item, trans->transid);