drivers/net/mlx4: Use %pV, pr_<level>, printk_once

Remove near duplication of format string constants by using the newly
introduced vsprintf extention %pV to reduce text by 20k or so.

$ size drivers/net/mlx4/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 161367	   1866	  48784	 212017	  33c31	drivers/net/mlx4/built-in.o
 142621	   1866	  46248	 190735	  2e90f	drivers/net/mlx4/built-in.o.new

Use printk_once as appropriate.
Convert printks to pr_<level>, some bare printks now use pr_cont.
Remove now unused #define PFX.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/mlx4/catas.c b/drivers/net/mlx4/catas.c
index f599294..68aaa42 100644
--- a/drivers/net/mlx4/catas.c
+++ b/drivers/net/mlx4/catas.c
@@ -101,8 +101,8 @@
 		ret = mlx4_restart_one(priv->dev.pdev);
 		/* 'priv' now is not valid */
 		if (ret)
-			printk(KERN_ERR "mlx4 %s: Reset failed (%d)\n",
-				pci_name(pdev), ret);
+			pr_err("mlx4 %s: Reset failed (%d)\n",
+			       pci_name(pdev), ret);
 		else {
 			dev  = pci_get_drvdata(pdev);
 			mlx4_dbg(dev, "Reset succeeded\n");