pgsql: Fix wording in comment

Fix wording in comment

The comment for the DSM_OP_CREATE paramater read "the a new handle"
which is confusing. Fix by rewording to indicate what the parameter
means for DSM_OP_CREATE.

Reported-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/CAEG8a3J2bc197ym-M_ykOXb9ox2eNn-QNKNeoSAoHYSw2NCOnw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/27a36f79b6d15cb2b267d16084007aa9d6917aec

Modified Files
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src/backend/storage/ipc/dsm_impl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)