linter: (1/2) enable errcheck (#5064)

## Description

partially cleanup in preparation for errcheck

i ignored a bunch of defer errors in tests but with the update to go 1.14 we can use `t.Cleanup(func() { if err := <>; err != nil {..}}` to cover those errors, I will do this in pr number two of enabling errcheck.

ref #5059

consensus/replay.go

@@ -128,7 +128,7 @@ func (cs *State) catchupReplay(csHeight int64) error {
 	if !found {
 		return fmt.Errorf("cannot replay height %d. WAL does not contain #ENDHEIGHT for %d", csHeight, csHeight-1)
 	}
-	defer gr.Close() // nolint: errcheck
+	defer gr.Close()
 
 	cs.Logger.Info("Catchup by replaying consensus messages", "height", csHeight)
 

consensus/replay_file.go

@@ -66,7 +66,7 @@ func (cs *State) ReplayFile(file string, console bool) error {
 	}
 
 	pb := newPlayback(file, fp, cs, cs.state.Copy())
-	defer pb.fp.Close() // nolint: errcheck
+	defer pb.fp.Close()
 
 	var nextN int // apply N msgs in a row
 	var msg *TimedWALMessage

consensus/replay_test.go

@@ -1002,7 +1002,7 @@ func makeBlockchainFromWAL(wal WAL) ([]*types.Block, []*types.Commit, error) {
 	if !found {
 		return nil, nil, fmt.Errorf("wal does not contain height %d", height)
 	}
-	defer gr.Close() // nolint: errcheck
+	defer gr.Close()
 
 	// log.Notice("Build a blockchain by reading from the WAL")