gocritic (1/2) (#3836)

Add gocritic as a linter

    The linting is not complete, but should i complete in this PR or in a following.

    23 files have been touched so it may be better to do in a following PR


Commits:

* Add gocritic to linting

- Added gocritic to linting

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* gocritic

* pr comments

* remove switch in cmdBatch

consensus/mempool_test.go

@@ -82,14 +82,14 @@ func TestMempoolProgressInHigherRound(t *testing.T) {
 	ensureNewRound(newRoundCh, height, round) // first round at first height
 	ensureNewEventOnChannel(newBlockCh)       // first block gets committed
 
-	height = height + 1 // moving to the next height
+	height++ // moving to the next height
 	round = 0
 
 	ensureNewRound(newRoundCh, height, round) // first round at next height
 	deliverTxsRange(cs, 0, 1)                 // we deliver txs, but dont set a proposal so we get the next round
 	ensureNewTimeout(timeoutCh, height, round, cs.config.TimeoutPropose.Nanoseconds())
 
-	round = round + 1                         // moving to the next round
+	round++                                   // moving to the next round
 	ensureNewRound(newRoundCh, height, round) // wait for the next round
 	ensureNewEventOnChannel(newBlockCh)       // now we can commit the block
 }