The FBI saw enough merit in a reputed Mafia captain’s tip to once again break out the digging equipment in search of the elusive remains of former Teamsters union leader Jimmy Hoffa, last seen alive when he left for lunch with two mobsters 38 years ago. Federal agents brought excavation equipment Monday to a field in suburban Detroit where Tony Zerilli said Hoffa’s remains were buried. Zerilli, 85, told Detroit television station WDIV in February that he knew the location of the remains. …