Fix misspellings of "system", "controller", "interrupt" and "necessary".

Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
diff --git a/drivers/ata/pata_cs5535.c b/drivers/ata/pata_cs5535.c
index 3578593..0132453 100644
--- a/drivers/ata/pata_cs5535.c
+++ b/drivers/ata/pata_cs5535.c
@@ -25,7 +25,7 @@
  * Documentation:
  *	Available from AMD web site.
  * TODO
- *	Review errata to see if serializing is neccessary
+ *	Review errata to see if serializing is necessary
  */
 
 #include <linux/kernel.h>