s390/qdio: sanitize put_indicator

qdio maintains an array of struct indicator_t. put_indicator takes a pointer
to a member of a struct indicator_t within that array, calculates the index,
and uses the array and the index to get the struct indicator_t.

Simply use the pointer directly.

Although the pointer happens to point to the first member of that struct
use the container_of macro.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/qdio_thinint.c

@@ -66,13 +66,11 @@ static u32 *get_indicator(void)
 
 static void put_indicator(u32 *addr)
 {
-	int i;
+	struct indicator_t *ind = container_of(addr, struct indicator_t, ind);
 
 	if (!addr)
 		return;
-	i = ((unsigned long)addr - (unsigned long)q_indicators) /
-		sizeof(struct indicator_t);
-	atomic_dec(&q_indicators[i].count);
+	atomic_dec(&ind->count);
 }
 
 void tiqdio_add_input_queues(struct qdio_irq *irq_ptr)