Fix build errors in promtool

Signed-off-by: Tobias Guggenmos <tguggenm@redhat.com>

cmd/promtool/unittest.go

@@ -31,6 +31,7 @@ import (
 
 	"github.com/prometheus/prometheus/pkg/labels"
 	"github.com/prometheus/prometheus/promql"
+	"github.com/prometheus/prometheus/promql/parser"
 	"github.com/prometheus/prometheus/rules"
 	"github.com/prometheus/prometheus/storage"
 )
@@ -339,7 +340,7 @@ Outer:
 
 		var expSamples []parsedSample
 		for _, s := range testCase.ExpSamples {
-			lb, err := promql.ParseMetric(s.Labels)
+			lb, err := parser.ParseMetric(s.Labels)
 			if err != nil {
 				err = errors.Wrapf(err, "labels %q", s.Labels)
 				errs = append(errs, errors.Errorf("    expr: %q, time: %s, err: %s", testCase.Expr,