Fix order of parameters in a cost_sort call

Fix order of parameters in a cost_sort call

In label_sort_with_costsize, the cost_sort function is called with the
parameters 'input_disabled_nodes' and 'input_cost' in the wrong order.
This does not cause any plan diffs in the regression tests, because
label_sort_with_costsize is only used to label the Sort node nicely
for EXPLAIN, and cost numbers are not displayed in regression tests.

Oversight in e22253467.  Fixed by passing arguments in the right
order.

Per report from Alexander Lakhin running UBSan.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/a9b7231d-68bc-f117-a07c-96688f3e6aef@gmail.com