address review comments

- remove lock from remote signer
 - remove some require.NoError's

privval/remote_signer.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"sync"
 
 	"github.com/pkg/errors"
 
@@ -19,7 +18,6 @@ import (
 type RemoteSignerClient struct {
 	conn            net.Conn
 	consensusPubKey crypto.PubKey
-	lock            sync.Mutex
 }
 
 // Check that RemoteSignerClient implements PrivValidator.
@@ -47,9 +45,6 @@ func (sc *RemoteSignerClient) GetPubKey() crypto.PubKey {
 }
 
 func (sc *RemoteSignerClient) getPubKey() (crypto.PubKey, error) {
-	sc.lock.Lock()
-	defer sc.lock.Unlock()
-
 	err := writeMsg(sc.conn, &PubKeyRequest{})
 	if err != nil {
 		return nil, err
@@ -73,9 +68,6 @@ func (sc *RemoteSignerClient) getPubKey() (crypto.PubKey, error) {
 
 // SignVote implements PrivValidator.
 func (sc *RemoteSignerClient) SignVote(chainID string, vote *types.Vote) error {
-	sc.lock.Lock()
-	defer sc.lock.Unlock()
-
 	err := writeMsg(sc.conn, &SignVoteRequest{Vote: vote})
 	if err != nil {
 		return err
@@ -103,9 +95,6 @@ func (sc *RemoteSignerClient) SignProposal(
 	chainID string,
 	proposal *types.Proposal,
 ) error {
-	sc.lock.Lock()
-	defer sc.lock.Unlock()
-
 	err := writeMsg(sc.conn, &SignProposalRequest{Proposal: proposal})
 	if err != nil {
 		return err
@@ -129,9 +118,6 @@ func (sc *RemoteSignerClient) SignProposal(
 
 // Ping is used to check connection health.
 func (sc *RemoteSignerClient) Ping() error {
-	sc.lock.Lock()
-	defer sc.lock.Unlock()
-
 	err := writeMsg(sc.conn, &PingRequest{})
 	if err != nil {
 		return err

privval/tcp_test.go

@@ -43,7 +43,6 @@ func TestSocketPVPubKey(t *testing.T) {
 	require.NoError(t, err)
 
 	privvalPubKey := rs.privVal.GetPubKey()
-	require.NoError(t, err)
 
 	assert.Equal(t, privvalPubKey, clientKey)
 }