[S390] qdio: fix compile warning under 31 bit

The QEBSM instructions are only available for CONFIG_64BIT, they are not
used under 31 bit. Make compiler happy about the false positive:

drivers/s390/cio/qdio_main.c: In function ?qdio_inbound_q_done?:
drivers/s390/cio/qdio_main.c:532: warning: ?state? may be used uninitialized in this function
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/qdio_main.c

@@ -529,7 +529,7 @@ int qdio_inbound_q_moved(struct qdio_q *q)
 
 static int qdio_inbound_q_done(struct qdio_q *q)
 {
-	unsigned char state;
+	unsigned char state = 0;
 #ifdef CONFIG_QDIO_DEBUG
 	char dbf_text[15];
 #endif

drivers/s390/cio/qdio_thinint.c

@@ -125,7 +125,7 @@ void tiqdio_remove_input_queues(struct qdio_irq *irq_ptr)
 
 static inline int tiqdio_inbound_q_done(struct qdio_q *q)
 {
-	unsigned char state;
+	unsigned char state = 0;
 
 	if (!atomic_read(&q->nr_buf_used))
 		return 1;