Use initial assignment of action to check for errors.

This simplifies things and make action = -1 no longer a dead store.
Also, spell FALLTHROUGH consistently.
reported by fritjof@alokat.org

src/usr.sbin/ntpd/client.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: client.c,v 1.97 2015/01/09 23:44:07 bcook Exp $ */
+/*	$OpenBSD: client.c,v 1.98 2015/01/19 20:47:03 bcook Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -85,7 +85,7 @@ client_addr_init(struct ntp_peer *p)
 			break;
 		default:
 			fatalx("king bula sez: wrong AF in client_addr_init");
-			/* not reached */
+			/* NOTREACHED */
 		}
 	}
 

src/usr.sbin/ntpd/ntpd.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.c,v 1.86 2015/01/14 21:14:27 naddy Exp $ */
+/*	$OpenBSD: ntpd.c,v 1.87 2015/01/19 20:47:03 bcook Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -578,12 +578,11 @@ ctl_main(int argc, char *argv[])
 		case 'a':
 			action = CTL_SHOW_ALL;
 			break;
-		default:
-			usage();
-			/* NOTREACHED */
 		}
-	} else
+	}
+	if (action == -1) 
 		usage();
+		/* NOTREACHED */
 
 	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
 		err(1, "ntpctl: socket");