[hackers] [ubase] Update umount usage || sin

[git]

commit 6506e85d1339ea0c6ed97dfbc88ac0d064f534e0
Author: sin <s...@2f30.org>
Date:   Wed Mar 12 16:28:56 2014 +0200

    Update umount usage

diff --git a/umount.c b/umount.c
index 514063d..2b0c32e 100644
--- a/umount.c
+++ b/umount.c
@@ -8,7 +8,9 @@
 static void
 usage(void)
 {
-       eprintf("usage: %s [-alfn] target
", argv0);
+       weprintf("usage: %s [-lfn] target
", argv0);
+       weprintf("usage: %s -a [-lfn]
", argv0);
+       exit(EXIT_FAILURE);
 }
 
 int