Silence another _bt_check_unique compiler warning.
Per complaint from Tom Lane
Discussion:
@@ -408,7 +408,7 @@ _bt_check_unique(Relation rel, BTInsertState insertstate, Relation heapRel,
{
IndexTuple itup = insertstate->itup;
IndexTuple curitup = NULL;
- ItemId curitemid;
+ ItemId curitemid = NULL;
BTScanInsert itup_key = insertstate->itup_key;
SnapshotData SnapshotDirty;
OffsetNumber offset;
