orinoco: correct key bounds check in orinoco_hw_get_tkip_iv

If key is 4 that is an array out of bounds.

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/orinoco/hw.c b/drivers/net/wireless/orinoco/hw.c
index 632fac8..b394627 100644
--- a/drivers/net/wireless/orinoco/hw.c
+++ b/drivers/net/wireless/orinoco/hw.c
@@ -70,7 +70,7 @@
 	int err = 0;
 	u8 tsc_arr[4][IW_ENCODE_SEQ_MAX_SIZE];
 
-	if ((key < 0) || (key > 4))
+	if ((key < 0) || (key >= 4))
 		return -EINVAL;
 
 	err = hermes_read_ltv(hw, USER_BAP, HERMES_RID_CURRENT_TKIP_IV,