maple_tree: Fix error in splitting on the right side

maple_tree: Fix error in splitting on the right side

When splitting on the right side, there were a number of logical
errors:
1. Finding the parents type needed the parent to be encoded, so move the
logic to a location better suited to use the encoded node.
2. ma_copy had an incorrect range (off by one).
3. mt_replace was not using the encoded node to find the parent's slot.
This would always return zero.
4. ma_link had a potential overflow in the pivot.
5. The ma_state's min/max was not being updated and so the pivots were
not always correct when using the min/max.
6. The data end detection needed to be updated to also check for
ULONG_MAX.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>