"Beverly Hills Cop II" looks like it will be the blockbuster it was expected to be. The Eddie Murphy crash-and-burn comedy grossed $33 million over the Memorial Day weekend, and after six full days in 2,326 theaters, it has taken in $40.6 million at the box office. The six-day figure assures "Beverly Hills Cop II" of having the third best opening week ever, trailing only "Indiana Jones and the Temple of Doom" and "Return of the Jedi." Among the other new entries, "Ernest Goes to Camp," a Disney/Touchstone release, also opened well, doing $6.2 million in 1541 theaters, while the Samuel Goldwyn Co.'s "The Chipmunk Adventure" did $2.6 million in 916 theaters. But there was more bad news for Columbia's "Ishtar." Despite the holiday, "Ishtar" grossed only $3.4 million in more than 1,100 theaters, down nearly $1 million from its opening weekend. Other holdovers still doing business were "The Secret of My Success" ($3.7 million) and "The Gate" ($2.9 million). Figures supplied by Exhibitor Relations Co.