iommu/iova: Unify format of the printed messages

Unify format of the printed messages, i.e. replace printk(LEVEL ... )
with pr_level(...).

Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Joerg Roedel <[e-mail]>

drivers/iommu/iova.c

···
 			SLAB_HWCACHE_ALIGN, NULL);
 		if (!iova_cache) {
 			mutex_unlock(&iova_cache_mutex);
-			printk(KERN_ERR "Couldn't create iova cache\n");
+			pr_err("Couldn't create iova cache\n");
 			return -ENOMEM;
 		}
 	}
···
 
 		new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
 		if (!new_iova)
-			printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",
-				iova->pfn_lo, iova->pfn_lo);
+			pr_err("Reserve iova range %lx@%lx failed\n",
+			       iova->pfn_lo, iova->pfn_lo);
 	}
 	spin_unlock_irqrestore(&from->iova_rbtree_lock, flags);
 }