More rows.Close() and rows.Err() (#3262)

Looks like we missed some `rows.Close()`

Even though `rows.Err()` is mostly not necessary, we should be more
consistent in the DB layer.

[skip ci]

syncapi/storage/postgres/current_room_state_table.go

@@ -392,7 +392,7 @@ func currentRoomStateRowsToStreamEvents(rows *sql.Rows) ([]types.StreamEvent, er
 		})
 	}
 
-	return events, nil
+	return events, rows.Err()
 }
 
 func rowsToEvents(rows *sql.Rows) ([]*rstypes.HeaderedEvent, error) {