ssh,acme: clean up tautological/impossible nil conditions

Change-Id: I4c6b4b6d8dc1e8a9d2ebfb8d350b7617d3cf7949
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/739780
Auto-Submit: Neal Patel <nealpatel@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Nicola Murino <nicola.murino@gmail.com>

acme/autocert/renewal_test.go

@@ -180,9 +180,6 @@ func TestRenewFromCacheAlreadyRenewed(t *testing.T) {
 
 	// set internal state to an almost expired cert
 	oldCert := ca.LeafCert(exampleDomain, "ECDSA", now.Add(-2*time.Hour), now.Add(time.Minute))
-	if err != nil {
-		t.Fatal(err)
-	}
 	oldLeaf, err := validCert(exampleCertKey, oldCert.Certificate, oldCert.PrivateKey.(crypto.Signer), now)
 	if err != nil {
 		t.Fatal(err)

ssh/agent/server.go

@@ -36,7 +36,7 @@ func (s *server) processRequestBytes(reqData []byte) []byte {
 		return []byte{agentFailure}
 	}
 
-	if err == nil && rep == nil {
+	if rep == nil {
 		return []byte{agentSuccess}
 	}
 

ssh/certs_test.go

@@ -330,10 +330,6 @@ func TestCertTypes(t *testing.T) {
 			go NewServerConn(c1, conf)
 
 			priv := m.signer
-			if err != nil {
-				t.Fatalf("error generating ssh pubkey: %v", err)
-			}
-
 			cert := &Certificate{
 				CertType: UserCert,
 				Key:      priv.PublicKey(),