s390/raw3270: add comment to spinlock member

Add a small comment to the lock member of struct raw3270_view
to make checkpatch happy.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

drivers/s390/char/raw3270.h

@@ -159,7 +159,7 @@ struct raw3270_fn {
  */
 struct raw3270_view {
 	struct list_head list;
-	spinlock_t lock;
+	spinlock_t lock; /* protects members of view */
 #define RAW3270_VIEW_LOCK_IRQ	0
 #define RAW3270_VIEW_LOCK_BH	1
 	atomic_t ref_count;