ixgbe: fix build when DEBUG is defined

The ixgbe driver had issues when DEBUG was defined because the hw_dbg macro
was incomplete.  This patch completes the code based off of the code that
already existed in the igb module.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 79aa811..fd27513 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -4987,8 +4987,20 @@
 
 	return ret_val ? NOTIFY_BAD : NOTIFY_DONE;
 }
-#endif /* CONFIG_IXGBE_DCA */
 
+#endif /* CONFIG_IXGBE_DCA */
+#ifdef DEBUG
+/**
+ * ixgbe_get_hw_dev_name - return device name string
+ * used by hardware layer to print debugging information
+ **/
+char *ixgbe_get_hw_dev_name(struct ixgbe_hw *hw)
+{
+	struct ixgbe_adapter *adapter = hw->back;
+	return adapter->netdev->name;
+}
+
+#endif
 module_exit(ixgbe_exit_module);
 
 /* ixgbe_main.c */