btrfs: convert printk(KERN_* to use pr_* calls

This patch converts printk(KERN_* style messages to use the pr_* versions.

One side effect is that anything that was KERN_DEBUG is now automatically
a dynamic debug message.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index e5ab27e..1f157fb 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -77,7 +77,7 @@
 		clear = BTRFS_FEATURE_INCOMPAT_SAFE_CLEAR;
 		break;
 	default:
-		printk(KERN_WARNING "btrfs: sysfs: unknown feature set %d\n",
+		pr_warn("btrfs: sysfs: unknown feature set %d\n",
 				fa->feature_set);
 		return 0;
 	}