xfs_repair: Fix malloc size of rt_ext_tree_ptr (harmless)

[Eric Sandeen <sandeen@xxxxxxxxxx>]

rt_ext_tree_ptr points to an avl64tree_desc_t, but we malloc memory
according to the size of avltree_desc_t.  Oddly, the latter happens
to be larger, so we're ok, but may as well make it correct.

Addresses-Coverity-Id: 1297533
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---

Hm, I thought I sent this already, but don't see it on the list.

diff --git a/repair/incore_ext.c b/repair/incore_ext.c
index 826bf44..6611d5c 100644
--- a/repair/incore_ext.c
+++ b/repair/incore_ext.c
@@ -783,7 +783,7 @@ incore_ext_init(xfs_mount_t *mp)
                avl_init_tree(extent_bcnt_ptrs[i], &avl_extent_bcnt_tree_ops);
        }
 
-       if ((rt_ext_tree_ptr = malloc(sizeof(avltree_desc_t))) == NULL)
+       if ((rt_ext_tree_ptr = malloc(sizeof(avl64tree_desc_t))) == NULL)
                do_error(_("couldn't malloc dup rt extent tree descriptor\n"));
 
        avl64_init_tree(rt_ext_tree_ptr, &avl64_extent_tree_ops);