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>

net/iucv/iucv.c

@@ -389,7 +389,7 @@ static void iucv_block_cpu(void *data)
  * iucv_declare_cpu
  * @data: unused
  *
- * Declare a interupt buffer on this cpu.
+ * Declare a interrupt buffer on this cpu.
  */
 static void iucv_declare_cpu(void *data)
 {