pgsql: pgbench: Restore compatibility of --partitions=0

pgbench: Restore compatibility of --partitions=0

A value of 0 is allowed for this option since its creation, that would
map with the default of having no partitions for pgbench_accounts, but
6f164e6 broke that by enforcing an error.  This commit restores the
original behavior.

Author: Amit Langote
Discussion: https://postgr.es/m/CA+HiwqGAGobiiHR8nH382HJxqm1mzZs8=3oKPXnXivWoFSZmNA@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/27f1366050c6cd8c1ea5f03b367a5a167ebf34b7

Modified Files
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src/bin/pgbench/pgbench.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)