import: fix incomplete successful imports during node failure

If a context cancellation occurs during import that aborts the
import-files-to-kv goroutine the ingestKvs goroutine could short circuit
and randomly not fail (ie not return an error) if the select chose the
progress arm over the done checking arm of its select.  This would
record the progress so that on subsequent import retries we'd think we
were done with those rows but we'd never actually have ingested them.
Fix this by only recording the progress if both goroutines sucessfully
complete without error.

Fixes: cockroachdb#108547
Epic: None

Release note (bug fix): Fixed a bug that could cause some rows to be
silently skipped during IMPORT when a node failed.

pkg/sql/importer/read_import_base.go

@@ -112,29 +112,26 @@ func runImport(
 	var summary *kvpb.BulkOpSummary
 	group.GoCtx(func(ctx context.Context) error {
 		summary, err = ingestKvs(ctx, flowCtx, spec, progCh, kvCh)
-		if err != nil {
-			return err
-		}
-		var prog execinfrapb.RemoteProducerMetadata_BulkProcessorProgress
-		prog.ResumePos = make(map[int32]int64)
-		prog.CompletedFraction = make(map[int32]float32)
-		for i := range spec.Uri {
-			prog.CompletedFraction[i] = 1.0
-			prog.ResumePos[i] = math.MaxInt64
-		}
-		select {
-		case <-ctx.Done():
-			return ctx.Err()
-		case progCh <- prog:
-			return nil
-		}
+		return err
 	})
 
 	if err = group.Wait(); err != nil {
 		return nil, err
 	}
 
-	return summary, nil
+	var prog execinfrapb.RemoteProducerMetadata_BulkProcessorProgress
+	prog.ResumePos = make(map[int32]int64)
+	prog.CompletedFraction = make(map[int32]float32)
+	for i := range spec.Uri {
+		prog.CompletedFraction[i] = 1.0
+		prog.ResumePos[i] = math.MaxInt64
+	}
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case progCh <- prog:
+		return summary, nil
+	}
 }
 
 type readFileFunc func(context.Context, *fileReader, int32, int64, chan string) error