mwifiex: fix potential out-of-boundary access to ibss rate table

smatch found this error:

CHECK   drivers/net/wireless/mwifiex/join.c
  drivers/net/wireless/mwifiex/join.c:1121
  mwifiex_cmd_802_11_ad_hoc_join()
  error: testing array offset 'i' after use.

Cc: <stable@vger.kernel.org> # 3.0+
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/net/wireless/mwifiex/join.c b/drivers/net/wireless/mwifiex/join.c
index 246aa62a4817..2fe0ceba4400 100644
--- a/drivers/net/wireless/mwifiex/join.c
+++ b/drivers/net/wireless/mwifiex/join.c
@@ -1117,10 +1117,9 @@ mwifiex_cmd_802_11_ad_hoc_join(struct mwifiex_private *priv,
                 adhoc_join->bss_descriptor.bssid,
                 adhoc_join->bss_descriptor.ssid);
 
-        for (i = 0; bss_desc->supported_rates[i] &&
-                        i < MWIFIEX_SUPPORTED_RATES;
-                        i++)
-                        ;
+        for (i = 0; i < MWIFIEX_SUPPORTED_RATES &&
+                    bss_desc->supported_rates[i]; i++)
+                ;
         rates_size = i;
 
         /* Copy Data Rates from the Rates recorded in scan response */