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/net/via-velocity.c b/drivers/net/via-velocity.c
index 4ae0579..5c4a92d 100644
--- a/drivers/net/via-velocity.c
+++ b/drivers/net/via-velocity.c
@@ -1648,7 +1648,7 @@
  *
  *	Scan the queues looking for transmitted packets that
  *	we can complete and clean up. Update any statistics as
- *	neccessary/
+ *	necessary/
  */
 
 static int velocity_tx_srv(struct velocity_info *vptr, u32 status)