iwlagn: transport layer receives struct iwl_trans*

It still holds a pointer to iwl_priv. But hopefully this will disappear at some point.
Also add the multiple inclusion protection to iwl-trans.h that was forgotten.
Move iwl-trans structures to iwl-trans.h

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
index f6ebe29..0505b1a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-scan.c
+++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
@@ -75,7 +75,7 @@
 	    test_bit(STATUS_EXIT_PENDING, &priv->status))
 		return -EIO;
 
-	ret = trans_send_cmd(priv, &cmd);
+	ret = trans_send_cmd(&priv->trans, &cmd);
 	if (ret)
 		return ret;