fixed os.path.splitext bug when using STDIN input

processing/pre/geom_fromVoronoiTessellation.py

@@ -196,7 +196,7 @@ if filenames == []: filenames = [None]
 for name in filenames:
   try:
     table = damask.ASCIItable(name = name,
-                              outname = os.path.splitext(name)[0]+'.geom',
+                              outname = os.path.splitext(name)[0]+'.geom' if name else name,
                               buffered = False)
   except: continue
   table.croak('\033[1m'+scriptName+'\033[0m'+(': '+name if name else ''))