iwlwifi: re-introduce per device debugging

Commit "iwlwifi: make debug level more user friendly" cleaned up the
debug level handling. In doing so it created a single global debug
level for all devices. Some setups do consits of more that one iwlwifi
device and in these setups there is a requirement that debug levels
should be unique per device.

We now re-introduce the per device debugging while maintaining the
cleanup effort of the previous patch.

The maintain the global debug level and now introduce a per-device debug
level that will be used if it (the per-device debug level) is set. The
per-device debug level can be controlled via the debug_level sysfs file
while the global debug level is controlled by the debug module parameter.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c
index efcae0d..def1254 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sta.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sta.c
@@ -1088,7 +1088,7 @@
 		IWL_DEBUG_DROP(priv, "Station %pM not in station map. "
 			       "Defaulting to broadcast...\n",
 			       hdr->addr1);
-		iwl_print_hex_dump(IWL_DL_DROP, (u8 *) hdr, sizeof(*hdr));
+		iwl_print_hex_dump(priv, IWL_DL_DROP, (u8 *) hdr, sizeof(*hdr));
 		return priv->hw_params.bcast_sta_id;
 
 	default: