pgsql: Prevent pg_enable/disable_data_checksums() on standby

Prevent pg_enable/disable_data_checksums() on standby

These functions missed a RecoveryInProgress() check, allowing them to
be called on a hot standby. Enabling, or disabling, checksums on the
standby only would cause the cluster to get out of sync and replaying
checksum transitions to fail.

Author: Satyanarayana Narlapuram <satyanarlapuram(at)gmail(dot)com>
Reviewed-by: Ayush Tiwari <ayushtiwari(dot)slg01(at)gmail(dot)com>
Reviewed-by: Tomas Vondra <tomas(at)vondra(dot)me>
Reviewed-by: Daniel Gustafsson <daniel(at)yesql(dot)se>
Discussion: https://postgr.es/m/CAHg+QDfRk4-S7DMmdbXJnQ-xF=sUpMAKuh8b83ObLqYVKx5QLA@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/b120358c612dce62b493da7682b4df90a10783c9

Modified Files
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src/backend/postmaster/datachecksum_state.c | 4 ++++
1 file changed, 4 insertions(+)