pgsql: Set LSN for wbuf in _hash_freeovflpage() iff wbuf is modified.

Set LSN for wbuf in _hash_freeovflpage() iff wbuf is modified.

Commit 861f86beea used REGBUF_NO_CHANGE at one of the places in the hash
index to register the clean buffers but forgot to avoid setting LSN in
that case.

Reported-by: Michael Paquier
Author: Kuroda Hayato
Reviewed-by: Amit Kapila, Michael Paquier
Discussion: https://postgr.es/m/ZbyVVG_7eW3YD5-A@paquier.xyz

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/aa5edbe379d645e980f927b01379bdad9bc6c295

Modified Files
--------------
src/backend/access/hash/hashovfl.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)