Revert some changes from #1881

[jaekwon]

As per the Oak audit report #20250110-OAK-07 (internal for now), there is a bug introduced via the moving of the condition in balance.

+       if balance >= -1 {
+               return node
+       }

is moved above, but this causes the tree to lean, and not correctly balance.

Further, we should revert the formatting changes to preserve the if/else condition so that it matches the original indentation, and match closely what is already well proven in the iavl implementation.