give perf test a properly separate name

When adding this perf test I failed to realize that the first
parameter is the name of the test, which we can then use in metabase
to find the right benchmark.  Fix this to give the benchmark a unique
name, so we can query it properly in metabase.

misc/test/performance_test.go

@@ -125,9 +125,9 @@ func TestPolicyPacks(t *testing.T) {
 	err := npmInstallCmd.Run()
 	assert.NoError(t, err)
 
-	benchmark := bench("aws-py-s3-folder", "aws", "go", "go")
+	benchmark := bench("policy-test", "aws", "go", "go")
 	opts := integration.ProgramTestOptions{
-		Dir:                    path.Join(getCwd(t), "..", "..", benchmark.Name),
+		Dir:                    path.Join(getCwd(t), "..", "..", "aws-go-s3-folder"),
 		UpdateCommandlineFlags: []string{fmt.Sprintf("--policy-pack=%s", policyPack)},
 		ExtraRuntimeValidation: func(t *testing.T, stack integration.RuntimeValidationStackInfo) {
 			assertHTTPResult(t, "http://"+stack.Outputs["website_url"].(string), nil, func(body string) bool {