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>

drivers/ata/libata-sff.c

@@ -2258,7 +2258,7 @@ EXPORT_SYMBOL_GPL(ata_sff_postreset);
  *	@qc: command
  *
  *	Drain the FIFO and device of any stuck data following a command
- *	failing to complete. In some cases this is neccessary before a
+ *	failing to complete. In some cases this is necessary before a
  *	reset will recover the device.
  *
  */