pgsql: Fix typo in header comment

Fix typo in header comment

Commit 4c04be9b0 accidentally left off the _id portion of the function
name in the header comment.

Author: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/CAEG8a3LP+ytnAXSzR=yiEaQrde+iCybMHsuPn9n=UN3puV_1tw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a04761ac77354930aebe7613b40bbdd749af5002

Modified Files
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src/backend/utils/adt/xid8funcs.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)