tree-wide: Assorted spelling fixes

In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Joe Perches <joe@perches.com>
Cc: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2834a01..e572ecc 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1365,7 +1365,7 @@
 
 		__tun_detach(tun);
 
-		/* If desireable, unregister the netdevice. */
+		/* If desirable, unregister the netdevice. */
 		if (!(tun->flags & TUN_PERSIST)) {
 			rtnl_lock();
 			if (dev->reg_state == NETREG_REGISTERED)