pgsql: Fix function reference in comment

Fix function reference in comment

Commit a61b1f748 renamed ExecCheckRTEPerms to ExecCheckPermissions
as part of a larger body of work, but missed this comment.  Fix by
updating the referenced function name to make the comment the same
as other occurrences.

Author: Koshi Shibagaki <shibagaki.koshi@fujitsu.com>
Discussion: https://postgr.es/m/OS3PR01MB653359ACBE8DBBE29EE2BC71FA909@OS3PR01MB6533.jpnprd01.prod.outlook.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/fb6fad6ef1bb94b5bfde01a83951ad7eda7764bc

Modified Files
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contrib/postgres_fdw/postgres_fdw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)