HID: steelseries: fix out of bound array access

The last field of the driver_data->leds[] array is used to store the
special toggle for setting all leds simultaneously, so we need to allocate
appropriate number of led_classdev pointers.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-steelseries.c

@@ -23,7 +23,8 @@
 #define SRWS1_NUMBER_LEDS 15
 struct steelseries_srws1_data {
 	__u16 led_state;
-	struct led_classdev *led[SRWS1_NUMBER_LEDS];
+	/* the last element is used for setting all leds simultaneously */
+	struct led_classdev *led[SRWS1_NUMBER_LEDS + 1];
 };
 #endif