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

types/genesis.go

@@ -72,10 +72,8 @@ func (genDoc *GenesisDoc) ValidateAndComplete() error {
 
 	if genDoc.ConsensusParams == nil {
 		genDoc.ConsensusParams = DefaultConsensusParams()
-	} else {
-		if err := genDoc.ConsensusParams.Validate(); err != nil {
-			return err
-		}
+	} else if err := genDoc.ConsensusParams.Validate(); err != nil {
+		return err
 	}
 
 	for i, v := range genDoc.Validators {

types/validator_set.go

@@ -121,7 +121,7 @@ func (vals *ValidatorSet) RescalePriorities(diffMax int64) {
 	ratio := (diff + diffMax - 1) / diffMax
 	if diff > diffMax {
 		for _, val := range vals.Validators {
-			val.ProposerPriority = val.ProposerPriority / ratio
+			val.ProposerPriority /= ratio
 		}
 	}
 }
@@ -525,7 +525,7 @@ func (vals *ValidatorSet) applyRemovals(deletes []*Validator) {
 // The 'allowDeletes' flag is set to false by NewValidatorSet() and to true by UpdateWithChangeSet().
 func (vals *ValidatorSet) updateWithChangeSet(changes []*Validator, allowDeletes bool) error {
 
-	if len(changes) <= 0 {
+	if len(changes) == 0 {
 		return nil
 	}