xfs: fold xfs_refcountbt_init_common into xfs_refcountbt_init_cursor

Make the levels initialization in xfs_refcountbt_init_cursor conditional
and merge the two helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/libxfs/xfs_refcount_btree.c

@@ -346,12 +346,15 @@ const struct xfs_btree_ops xfs_refcountbt_ops = {
 };
 
 /*
- * Initialize a new refcount btree cursor.
+ * Create a new refcount btree cursor.
+ *
+ * For staging cursors tp and agbp are NULL.
  */
-static struct xfs_btree_cur *
-xfs_refcountbt_init_common(
+struct xfs_btree_cur *
+xfs_refcountbt_init_cursor(
 	struct xfs_mount	*mp,
 	struct xfs_trans	*tp,
+	struct xfs_buf		*agbp,
 	struct xfs_perag	*pag)
 {
 	struct xfs_btree_cur	*cur;
@@ -364,23 +367,12 @@ xfs_refcountbt_init_common(
 	cur->bc_ag.pag = xfs_perag_hold(pag);
 	cur->bc_refc.nr_ops = 0;
 	cur->bc_refc.shape_changes = 0;
-	return cur;
-}
-
-/* Create a btree cursor. */
-struct xfs_btree_cur *
-xfs_refcountbt_init_cursor(
-	struct xfs_mount	*mp,
-	struct xfs_trans	*tp,
-	struct xfs_buf		*agbp,
-	struct xfs_perag	*pag)
-{
-	struct xfs_agf		*agf = agbp->b_addr;
-	struct xfs_btree_cur	*cur;
-
-	cur = xfs_refcountbt_init_common(mp, tp, pag);
-	cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);
 	cur->bc_ag.agbp = agbp;
+	if (agbp) {
+		struct xfs_agf		*agf = agbp->b_addr;
+
+		cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);
+	}
 	return cur;
 }
 
@@ -393,7 +385,7 @@ xfs_refcountbt_stage_cursor(
 {
 	struct xfs_btree_cur	*cur;
 
-	cur = xfs_refcountbt_init_common(mp, NULL, pag);
+	cur = xfs_refcountbt_init_cursor(mp, NULL, NULL, pag);
 	xfs_btree_stage_afakeroot(cur, afake);
 	return cur;
 }