After commit abb678b6
(a follow-up fix to MDEV-19514 to prevent potential hangs)
and MDEV-23399, the probability for hitting a dormant bug
that is related to MDEV-19514 was increased.

buf_page_create(): Call ibuf_merge_or_delete_for_page() also
when reusing a previously freed page.

Reviewed by: Thirunarayanan Balathandayuthapani