CLEVELAND — Donovan Mitchell tied an NBA playoff record with 39 points in the second half and the Cleveland Cavaliers evened their second-round series against the Detroit Pistons with a 112-103 victory Monday night. Mitchell matched the mark of Eric “Sleepy” Floyd on a free throw with 27.6 seconds remaining. He had a chance to break the record, set in 1987 against the Los Angeles Lakers, but missed his second foul shot. Mitchell finished with 43 points, including 15 during Cleveland’s 24-0 run that went from the last 12 seconds of the first half to the first six minutes of the third quarter. Cleveland trailed 56-52 at halftime before taking control. Donovan Mitchell reacts during the Cavaliers’ May 11 game against the Pistons. NBAE via Getty Images The Cavs were 10 of 12 from the field and made three 3-pointers. They also converted five turnovers by the Pistons into nine points.…