Last night's Cameron Diaz-hosted edition of Saturday Night Live scored points off the ever-expanding tribulations of Bill Cosby in a “Weekend Update” blast from co-anchorMichael Che. “Hey Bill Cosby, pull your damn pants up,” Che opened, admitting, “I've always wanted to say that.” It was a pointed reference to Cosby's frequent lecturing of African-American men on their responsibilities as husbands and fathers -- a posture that's taken it on the chin…