pb-4943: Added fix to return proper error message, if the kdmp backup

fails in DataExportStageTransferInProgress stage.

	- Currently, we are passing empty reason for the failed case, so
	  the reason is not passed to the UI. In the failed case, it shows empty reason.

pkg/controllers/dataexport/reconcile.go

@@ -376,13 +376,19 @@ func (c *Controller) sync(ctx context.Context, in *kdmpapi.DataExport) (bool, er
 		}
 		return true, c.updateStatus(dataExport, data)
 	case kdmpapi.DataExportStageTransferInProgress:
+		var reason string
+		if dataExport.Status.Status == kdmpapi.DataExportStatusSuccessful {
+			reason = ""
+		} else {
+			reason = dataExport.Status.Reason
+		}
 		if dataExport.Status.Status == kdmpapi.DataExportStatusSuccessful ||
 			dataExport.Status.Status == kdmpapi.DataExportStatusFailed {
 			// set to the next stage
 			data := updateDataExportDetail{
 				stage:  kdmpapi.DataExportStageCleanup,
 				status: dataExport.Status.Status,
-				reason: "",
+				reason: reason,
 			}
 			return false, c.updateStatus(dataExport, data)
 		}