fix the device demo usage message, and don't pause (not needed)
diff --git a/demo/device_demo.c b/demo/device_demo.c
index 4f437d3..f6a8ddd 100644
--- a/demo/device_demo.c
+++ b/demo/device_demo.c
@@ -218,7 +218,6 @@
         fprintf (stderr, "nn_device: %s\n", nn_strerror (nn_errno ()));
         return (-1);
     }
-    pause();
     return (0);
 }
 
@@ -233,9 +232,9 @@
     } else if ((argc == 4) && (strcmp (argv[1], "-c") == 0)) {
         rc = client (argv[2], argv[3]);
     } else {
-        fprintf (stderr, "Usage: %s -s <serverurl>", argv[0]);
-        fprintf (stderr, "Usage: %s -d <serverurl> <clienturl>", argv[0]);
-        fprintf (stderr, "Usage: %s -c <clienturl> <name>", argv[0]);
+        fprintf (stderr, "Usage: %s -s <serverurl>\n", argv[0]);
+        fprintf (stderr, "Usage: %s -d <serverurl> <clienturl>\n", argv[0]);
+        fprintf (stderr, "Usage: %s -c <clienturl> <name>\n", argv[0]);
         exit (EXIT_FAILURE);
     }