pgsql: Fix typo in GetRunningTransactionData()

Fix typo in GetRunningTransactionData()

e85662df44 made GetRunningTransactionData() calculate the oldest running
transaction id within the current database.  However, because of the typo,
the new code uses oldestRunningXid instead of oldestDatabaseRunningXid
in comparison before updating oldestDatabaseRunningXid.  This commit fixes
that issue.

Reported-by: Noah Misch
Discussion: https://postgr.es/m/20240630231816.bf.nmisch%40google.com
Backpatch-through: 17

Branch
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REL_17_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/619f76cce11dc51458eb4ea81b0e48d15d0b2d07

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