[S390] cio: airq - fix array boundary

MAX_ISC is a valid isc number, so arrays with an index of isc
need to have a length of MAX_ISC+1
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/airq.c

@@ -34,8 +34,8 @@ struct airq_t {
 	void *drv_data;
 };
 
-static union indicator_t indicators[MAX_ISC];
-static struct airq_t *airqs[MAX_ISC][NR_AIRQS];
+static union indicator_t indicators[MAX_ISC+1];
+static struct airq_t *airqs[MAX_ISC+1][NR_AIRQS];
 
 static int register_airq(struct airq_t *airq, u8 isc)
 {