lint: various fixes

## Description

various linitng fixes

p2p/node_info_test.go

@@ -1,7 +1,6 @@
 package p2p
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -24,8 +23,8 @@ func TestNodeInfoValidate(t *testing.T) {
 	dupChannels = append(dupChannels, testCh)
 
 	nonASCII := "¢§µ"
-	emptyTab := fmt.Sprintf("\t")
-	emptySpace := fmt.Sprintf("  ")
+	emptyTab := "\t"
+	emptySpace := "  "
 
 	testCases := []struct {
 		testName         string

p2p/pex/pex_reactor.go

@@ -11,7 +11,6 @@ import (
 
 	"github.com/tendermint/tendermint/libs/cmap"
 	tmmath "github.com/tendermint/tendermint/libs/math"
-	"github.com/tendermint/tendermint/libs/rand"
 	tmrand "github.com/tendermint/tendermint/libs/rand"
 	"github.com/tendermint/tendermint/libs/service"
 	"github.com/tendermint/tendermint/p2p"
@@ -409,7 +408,7 @@ func (r *Reactor) SetEnsurePeersPeriod(d time.Duration) {
 // Ensures that sufficient peers are connected. (continuous)
 func (r *Reactor) ensurePeersRoutine() {
 	var (
-		seed   = rand.NewRand()
+		seed   = tmrand.NewRand()
 		jitter = seed.Int63n(r.ensurePeersPeriod.Nanoseconds())
 	)
 
@@ -545,8 +544,8 @@ func (r *Reactor) dialPeer(addr *p2p.NetAddress) error {
 
 	// exponential backoff if it's not our first attempt to dial given address
 	if attempts > 0 {
-		jitterSeconds := time.Duration(tmrand.Float64() * float64(time.Second)) // 1s == (1e9 ns)
-		backoffDuration := jitterSeconds + ((1 << uint(attempts)) * time.Second)
+		jitter := time.Duration(tmrand.Float64() * float64(time.Second)) // 1s == (1e9 ns)
+		backoffDuration := jitter + ((1 << uint(attempts)) * time.Second)
 		backoffDuration = r.maxBackoffDurationForPeer(addr, backoffDuration)
 		sinceLastDialed := time.Since(lastDialed)
 		if sinceLastDialed < backoffDuration {