pgsql: Use REGBUF_NO_CHANGE at one more place in the hash index.

Use REGBUF_NO_CHANGE at one more place in the hash index.

Commit 00d7fb5e2e started to use REGBUF_NO_CHANGE at a few places in the
code where we register the buffer before marking it dirty but missed
updating one of the code flows in the hash index where we free the overflow
page without any live tuples on it.

Author: Amit Kapila and Hayato Kuroda
Discussion: http://postgr.es/m/f045c8f7-ee24-ead6-3679-c04a43d21351@gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/861f86beea1c241943a3ef000e789f18bbc8b7e8

Modified Files
--------------
src/backend/access/hash/hash_xlog.c      |  5 +++-
src/backend/access/hash/hashovfl.c       | 19 ++++++++++++++-
src/test/regress/expected/hash_index.out | 29 +++++++++++++++++++++++
src/test/regress/sql/hash_index.sql      | 40 ++++++++++++++++++++++++++++++++
4 files changed, 91 insertions(+), 2 deletions(-)