Task #3877: Minor fix to let vdsmaker bail out early, if none of the makevds...

Task #3877: Minor fix to let vdsmaker bail out early, if none of the makevds processes succeeded. Avoids incomprehensible error message from combinevds.

CEP/Pipeline/recipes/sip/master/vdsmaker.py

@@ -107,6 +107,9 @@ class vdsmaker(BaseRecipe, RemoteCommandRecipeMixIn):
             vds for vds, job in zip(vdsnames, jobs) 
             if job.results['returncode'] == 0
         ]
+        if not vdsnames:
+            self.logger.error("All makevds processes failed. Bailing out!")
+            return 1
 
         # *********************************************************************
         # 3. Combine VDS files to produce GDS