pgsql: Fix mixups of FooGetDatum() vs. DatumGetFoo()

Fix mixups of FooGetDatum() vs. DatumGetFoo()

Some of these were accidentally reversed, but there was no ill effect.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/8246d7ff-f4b7-4363-913e-827dadfeb145%40eisentraut.org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1469e312977c8a5baeb1f9cb4222d171faf285b3

Modified Files
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contrib/pageinspect/btreefuncs.c        | 2 +-
contrib/pageinspect/gistfuncs.c         | 4 ++--
src/backend/access/common/printsimple.c | 2 +-
src/backend/access/nbtree/nbtcompare.c  | 4 ++--
src/backend/access/transam/xlog.c       | 6 +++---
5 files changed, 9 insertions(+), 9 deletions(-)