all: use gometalinter.v2, fix new gosimple issues (#15650)

consensus/clique/clique.go

@@ -630,7 +630,7 @@ 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.Unix(header.Time.Int64(), 0).Sub(time.Now()) // nolint: gosimple
 	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