s390/3270: drop unused spinlock from struct con3270

I was checking why this spinlock was never initialized, but it turns
out it's not used anywhere, so we can drop it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/char/con3270.c

@@ -35,7 +35,6 @@ static struct raw3270_fn con3270_fn;
  */
 struct con3270 {
 	struct raw3270_view view;
-	spinlock_t lock;
 	struct list_head freemem;	/* list of free memory for strings. */
 
 	/* Output stuff. */