do not create fifo if not there

client-barcode/freitagskasse.py

@@ -35,16 +35,11 @@ display_fifo = None
 
 def print_display(s):
 	global display_fifo
-	""" 
-	Comment out this return for now if you dont 
-	want to use the display.
-
-	return
-
-	"""
 	if not display_fifo:
 		try:
-			display_fifo = open('/tmp/display', 'w')
+			#display_fifo = open('/tmp/display', 'w')
+			fd = os.open( "/tmp/display", os.O_WRONLY)
+			display_fifo = os.fdopen(fd,"w")
 		except IOError:
 			display_fifo = None
 			return