FORT WORTH, Texas — TCU did not have long to sniff the aroma left from the egg they laid Tuesday against Texas. That’s probably for the best. The Horned Frogs had no choice but to quickly air out Schollmaier Arena against No. 19 LSU Saturday morning. But against the nation’s top-rated defense, it wasn’t easy. After building a 16-point lead early in the second half, the Frogs had to hold off a persistent LSU rally to hold on for a 77-68 win. It’s TCU’s second win against a top-25 team in the past week. They pummeled Iowa State in Ames on Jan. 22, which only adds confusion to the manor in which …