By Lisandra Paraguassu and Peter Frontini SAO PAULO (Reuters) -Brazil’s leftist presidential candidate Luiz Inacio Lula da Silva maintains a clear lead over right-wing President Jair Bolsonaro, a poll showed on Wednesday, as the candidates scrambled to win over voters ahead of an Oct. 30 runoff. The survey by IPEC taken over the three days since the first-round vote found Lula with 51% voter support against Bolsonaro’s 43%, with a margin of error of two percentage points. IPEC was one of several polling firms criticized for underestimating Bolsonaro’s support in the first-round vote, which Lul…