Besieged Riverside General Hospital, which is facing legal and financial woes on multiple fronts, surrendered its license Thursday to provide substance abuse treatment as part of a bid to find a way to stay in business, even if in a reduced capacity. The move came after the state's top health official traveled to Houston for a tour of the facility's three campuses, in which he got a first-hand look at problems with everything from fire alarms and air conditioning filters to patients records and the condition of the kitchen.