iwlwifi: move iwl_free_skb and mark it static

iwl_free_skb is used only in iwl-agn.c, move
it there and mark it static.

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 208b827..7398535 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -2208,6 +2208,15 @@
 	priv->passive_no_rx = false;
 }
 
+static void iwl_free_skb(struct iwl_op_mode *op_mode, struct sk_buff *skb)
+{
+	struct ieee80211_tx_info *info;
+
+	info = IEEE80211_SKB_CB(skb);
+	kmem_cache_free(iwl_tx_cmd_pool, (info->driver_data[1]));
+	dev_kfree_skb_any(skb);
+}
+
 const struct iwl_op_mode_ops iwl_dvm_ops = {
 	.start = iwl_op_mode_dvm_start,
 	.stop = iwl_op_mode_dvm_stop,