DragonFlyBSD

This cleanup patch lets cursor climb up deep/fat btree slightly faster (lightweight), if not slower.

The local variable enospc won't be anything other than 0 at this point thus (&& enospc == 0) isn't necessary here. Also node type checking is redundant as they both use btree_node_is_full(). There used to be btree_node_is_almost_full() and internal/leaf needed to be separated by if/else but not anymore.