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/media/dvb/ttusb-budget/dvb-ttusb-budget.c b/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
index 288e79f..7902ae1 100644
--- a/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
+++ b/drivers/media/dvb/ttusb-budget/dvb-ttusb-budget.c
@@ -128,7 +128,7 @@
 	struct dvb_frontend* fe;
 };
 
-/* ugly workaround ... don't know why it's neccessary to read */
+/* ugly workaround ... don't know why it's necessary to read */
 /* all result codes. */
 
 #define DEBUG 0