fix vet error

test/insecure_creds_test.go

@@ -48,10 +48,6 @@ func (cr testLegacyPerRPCCredentials) RequireTransportSecurity() bool {
 	return true
 }
 
-func isExpectedError(got, want error) bool {
-	return status.Code(got) == status.Code(want) && strings.Contains(status.Convert(got).Message(), status.Convert(want).Message())
-}
-
 // TestInsecureCreds tests the use of insecure creds on the server and client
 // side, and verifies that expect security level and auth info are returned.
 // Also verifies that this credential can interop with existing `WithInsecure`
@@ -197,6 +193,9 @@ func (s) TestInsecureCredsWithPerRPCCredentials(t *testing.T) {
 
 			if test.perRPCCredsViaCallOptions {
 				cc, err := grpc.DialContext(ctx, addr, cOpts...)
+				if err != nil {
+					t.Fatalf("grpc.Dial(%q) failed: %v", addr, err)
+				}
 				defer cc.Close()
 
 				c := testpb.NewTestServiceClient(cc)