iwlwifi: fix possible NULL dereference in iwl_set_rate()

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl3945-base.c

@@ -2915,6 +2915,10 @@ static void iwl_set_rate(struct iwl_priv *priv)
 	int i;
 
 	hw = iwl_get_hw_mode(priv, priv->phymode);
+	if (!hw) {
+		IWL_ERROR("Failed to set rate: unable to get hw mode\n");
+		return;
+	}
 
 	priv->active_rate = 0;
 	priv->active_rate_basic = 0;

drivers/net/wireless/iwlwifi/iwl4965-base.c

@@ -3003,6 +3003,10 @@ static void iwl_set_rate(struct iwl_priv *priv)
 	int i;
 
 	hw = iwl_get_hw_mode(priv, priv->phymode);
+	if (!hw) {
+		IWL_ERROR("Failed to set rate: unable to get hw mode\n");
+		return;
+	}
 
 	priv->active_rate = 0;
 	priv->active_rate_basic = 0;