Fix Commit validation psuedocode

[ebuchman]

Commit validation looks like this:

for i, commitSig := range block.LastCommit.Signatures {
  if commitSig.Absent() {
    continue
  }

  vote.BlockID == block.LastBlockID

  val := state.LastValidators[i]
  vote.Verify(block.ChainID, val.PubKey) == true

  talliedVotingPower += val.VotingPower
}

Note the undefined vote type being used. Should be fixed to properly use the commitSig

[cmwaters]

I believe this issue is no longer relevant and we can close this.