consensus: fix megacheck warnings

consensus/clique/clique.go

@@ -619,7 +619,7 @@ func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-ch
 		}
 	}
 	// Sweet, the protocol permits us to sign the block, wait for our time
-	delay := time.Unix(header.Time.Int64(), 0).Sub(time.Now())
+	delay := time.Until(time.Unix(header.Time.Int64(), 0))
 	if header.Difficulty.Cmp(diffNoTurn) == 0 {
 		// It's not our turn explicitly to sign, delay it a bit
 		wiggle := time.Duration(len(snap.Signers)/2+1) * wiggleTime

consensus/clique/snapshot.go

@@ -229,9 +229,9 @@ func (s *Snapshot) apply(headers []*types.Header) (*Snapshot, error) {
 		// Tally up the new vote from the signer
 		var authorize bool
 		switch {
-		case bytes.Compare(header.Nonce[:], nonceAuthVote) == 0:
+		case bytes.Equal(header.Nonce[:], nonceAuthVote):
 			authorize = true
-		case bytes.Compare(header.Nonce[:], nonceDropVote) == 0:
+		case bytes.Equal(header.Nonce[:], nonceDropVote):
 			authorize = false
 		default:
 			return nil, errInvalidVote