pgsql: pg_dump: Set private_date pointer to NULL in callback

pg_dump: Set private_date pointer to NULL in callback

The end callback for ZStandard compression frees the private_data
but didn't set the pointer to NULL after freeing. This is not a
bug as the code is right now, since nothing is dereferencing the
pointer upon returning from the callback but it is good practice
to do.

Author: Alexander Kuznetsov <kuznetsovam(at)altlinux(dot)org>
Reviewed-by: Daniel Gustafsson <daniel(at)yesql(dot)se>
Reviewed-by: Ashutosh Bapat <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com>
Reviewed-by: Michael Paquier <michael(at)paquier(dot)xyz>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Discussion: https://postgr.es/m/efaee52b-9550-44ca-8633-ea86076b3283@altlinux.org

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/b669293e3432ee8fdcd44854a945837bb18eea5c

Modified Files
--------------
src/bin/pg_dump/compress_zstd.c | 1 +
1 file changed, 1 insertion(+)