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>

arch/x86/kernel/tsc.c

@@ -50,7 +50,7 @@ u64 native_sched_clock(void)
 	 *   unstable. We do this because unlike Time Of Day,
 	 *   the scheduler clock tolerates small errors and it's
 	 *   very important for it to be as fast as the platform
-	 *   can achive it. )
+	 *   can achieve it. )
 	 */
 	if (unlikely(tsc_disabled)) {
 		/* No locking but a rare wrong value is not a big deal: */