libertas: Read buffer overflow

Check whether index is within bounds before testing the element.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/11d.c b/drivers/net/wireless/libertas/11d.c
index 9a5408e..5c69681 100644
--- a/drivers/net/wireless/libertas/11d.c
+++ b/drivers/net/wireless/libertas/11d.c
@@ -47,7 +47,7 @@
 {
 	u8 i;
 
-	for (i = 0; region[i] && i < COUNTRY_CODE_LEN; i++)
+	for (i = 0; i < COUNTRY_CODE_LEN && region[i]; i++)
 		region[i] = toupper(region[i]);
 
 	for (i = 0; i < ARRAY_SIZE(region_code_mapping); i++) {