Remove Controller stats for export (#4500)

Export doesn't pull meaningful stats from the controller. Just remove
the collection/usage of these stats since it's confusing. Substitute the
check for not doing anything from a check on stats to a check on the
number of collections returned by kopia.

---

#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [x] 🧹 Tech Debt/Cleanup

#### Issue(s)

* #4254

#### Test Plan

- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

src/internal/operations/export.go

@@ -97,7 +97,6 @@ func (op ExportOperation) validate() error {
 // get populated asynchronously.
 type exportStats struct {
 	cs            []data.RestoreCollection
-	ctrl          *data.CollectionStats
 	bytesRead     *stats.ByteCounter
 	resourceCount int
 
@@ -274,10 +273,6 @@ func (op *ExportOperation) do(
 		return nil, clues.Stack(err)
 	}
 
-	opStats.ctrl = op.ec.Wait()
-
-	logger.Ctx(ctx).Debug(opStats.ctrl)
-
 	if op.ExportCfg.Archive {
 		zc, err := archive.ZipExportCollection(ctx, expCollections)
 		if err != nil {
@@ -309,17 +304,11 @@ func (op *ExportOperation) finalizeMetrics(
 	op.Results.ItemsRead = len(opStats.cs) // TODO: file count, not collection count
 	op.Results.ResourceOwners = opStats.resourceCount
 
-	if opStats.ctrl == nil {
+	if op.Status != Failed && op.Results.ItemsRead == 0 {
-		op.Status = Failed
-		return clues.New("restoration never completed")
-	}
-
-	if op.Status != Failed && opStats.ctrl.IsZero() {
 		op.Status = NoData
 	}
 
 	// We don't have data on what all items were written
-	// op.Results.ItemsWritten = opStats.ctrl.Successes
 
 	return op.Errors.Failure()
 }

src/internal/operations/export_test.go

@@ -65,10 +65,6 @@ func (suite *ExportUnitSuite) TestExportOperation_PersistResults() {
 						Collection: &exchMock.DataCollection{},
 					},
 				},
-				ctrl: &data.CollectionStats{
-					Objects:   1,
-					Successes: 1,
-				},
 			},
 		},
 		{
@@ -77,7 +73,6 @@ func (suite *ExportUnitSuite) TestExportOperation_PersistResults() {
 			fail:         assert.AnError,
 			stats: exportStats{
 				bytesRead: &stats.ByteCounter{},
-				ctrl:      &data.CollectionStats{},
 			},
 		},
 		{
@@ -86,7 +81,6 @@ func (suite *ExportUnitSuite) TestExportOperation_PersistResults() {
 			stats: exportStats{
 				bytesRead: &stats.ByteCounter{},
 				cs:        []data.RestoreCollection{},
-				ctrl:      &data.CollectionStats{},
 			},
 		},
 	}