ocfs2: Change ocfs2_get_*_extent_tree() to ocfs2_init_*_extent_tree()

The original get/put_extent_tree() functions held a reference on
et_root_bh.  However, every single caller already has a safe reference,
making the get/put cycle irrelevant.

We change ocfs2_get_*_extent_tree() to ocfs2_init_*_extent_tree().  It
no longer gets a reference on et_root_bh.  ocfs2_put_extent_tree() is
removed.  Callers now have a simpler init+use pattern.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index 2cdc553..167e6c9 100644
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -1194,7 +1194,7 @@
 	handle_t *handle;
 	struct ocfs2_extent_tree et;
 
-	ocfs2_get_dinode_extent_tree(&et, dir, di_bh);
+	ocfs2_init_dinode_extent_tree(&et, dir, di_bh);
 
 	alloc = ocfs2_clusters_for_bytes(sb, bytes);
 
@@ -1363,7 +1363,6 @@
 
 	brelse(dirdata_bh);
 
-	ocfs2_put_extent_tree(&et);
 	return ret;
 }
 
@@ -1485,9 +1484,8 @@
 	spin_lock(&OCFS2_I(dir)->ip_lock);
 	if (dir_i_size == ocfs2_clusters_to_bytes(sb, OCFS2_I(dir)->ip_clusters)) {
 		spin_unlock(&OCFS2_I(dir)->ip_lock);
-		ocfs2_get_dinode_extent_tree(&et, dir, parent_fe_bh);
+		ocfs2_init_dinode_extent_tree(&et, dir, parent_fe_bh);
 		num_free_extents = ocfs2_num_free_extents(osb, dir, &et);
-		ocfs2_put_extent_tree(&et);
 		if (num_free_extents < 0) {
 			status = num_free_extents;
 			mlog_errno(status);