btrfs: use explicit initializer for seq_elem

Using {} as initializer for struct seq_elem does not properly initialize
the list_head member, but it currently works because it gets set through
btrfs_get_tree_mod_seq if 'seq' is 0.

Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 97159a8..7f7eb39 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1845,7 +1845,7 @@
 	struct ulist *roots = NULL;
 	struct ulist *qgroups, *tmp;
 	struct btrfs_qgroup *qgroup;
-	struct seq_list elem = {};
+	struct seq_list elem = SEQ_LIST_INIT(elem);
 	u64 seq;
 	int old_roots = 0;
 	int new_roots = 0;
@@ -1967,7 +1967,7 @@
 	int err;
 	struct btrfs_qgroup *qg;
 	u64 root_obj = 0;
-	struct seq_list elem = {};
+	struct seq_list elem = SEQ_LIST_INIT(elem);
 
 	parents = ulist_alloc(GFP_NOFS);
 	if (!parents)
@@ -2522,7 +2522,7 @@
 {
 	struct btrfs_key found;
 	struct ulist *roots = NULL;
-	struct seq_list tree_mod_seq_elem = {};
+	struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
 	u64 num_bytes;
 	u64 seq;
 	int new_roots;