bug would only surface if the InnoDB SQL interpreter were used for
updating fixed-length columns.  Currently (as the UPD_NODE_NO_SIZE_CHANGE
flag is never set), cmpl_info can only be 0 or UPD_NODE_NO_ORD_CHANGE.
Luckily, UPD_NODE_NO_ORD_CHANGE is 1, and the condition was simplified
to !cmpl_info.