DashboardService: Consolidate constructors (#31886)

* DashboardService: Consolidate constructors

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

pkg/services/provisioning/dashboards/file_reader_linux_test.go

@@ -7,6 +7,8 @@ import (
 	"testing"
 
 	"github.com/grafana/grafana/pkg/infra/log"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 var (
@@ -23,18 +25,11 @@ func TestProvisionedSymlinkedFolder(t *testing.T) {
 	}
 
 	reader, err := NewDashboardFileReader(cfg, log.New("test-logger"))
-	if err != nil {
-		t.Error("expected err to be nil")
-	}
+	require.NoError(t, err)
 
 	want, err := filepath.Abs(containingID)
-
-	if err != nil {
-		t.Errorf("expected err to be nil")
-	}
+	require.NoError(t, err)
 
 	resolvedPath := reader.resolvedPath()
-	if resolvedPath != want {
-		t.Errorf("got %s want %s", resolvedPath, want)
-	}
+	assert.Equal(t, want, resolvedPath)
 }