iwlagn: add comments to iwl_bus / iwl_trans

Rename the recursive inclusion protection in iwl-bus.h while we are at it.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-trans.h b/drivers/net/wireless/iwlwifi/iwl-trans.h
index eec25b4..4a0c786 100644
--- a/drivers/net/wireless/iwlwifi/iwl-trans.h
+++ b/drivers/net/wireless/iwlwifi/iwl-trans.h
@@ -130,6 +130,11 @@
 	void (*free)(struct iwl_priv *priv);
 };
 
+/**
+ * struct iwl_trans - transport common data
+ * @ops - pointer to iwl_trans_ops
+ * @shrd - pointer to iwl_shared which holds shared data from the upper layer
+ */
 struct iwl_trans {
 	const struct iwl_trans_ops *ops;
 	struct iwl_shared *shrd;