Btrfs: convert printk to btrfs_ and fix BTRFS prefix

Convert all applicable cases of printk and pr_* to the btrfs_* macros.

Fix all uses of the BTRFS prefix.

Signed-off-by: Frank Holton <fholton@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 026f1fe..46bfd82 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -198,10 +198,10 @@
 	 */
 	smp_mb();
 	if (!list_empty(&fs_info->tree_mod_seq_list))
-		WARN(1, KERN_ERR "btrfs: tree_mod_seq_list not empty when "
+		WARN(1, KERN_ERR "BTRFS: tree_mod_seq_list not empty when "
 			"creating a fresh transaction\n");
 	if (!RB_EMPTY_ROOT(&fs_info->tree_mod_log))
-		WARN(1, KERN_ERR "btrfs: tree_mod_log rb tree not empty when "
+		WARN(1, KERN_ERR "BTRFS: tree_mod_log rb tree not empty when "
 			"creating a fresh transaction\n");
 	atomic64_set(&fs_info->tree_mod_seq, 0);
 
@@ -1107,7 +1107,7 @@
 			break;
 
 		if (btrfs_defrag_cancelled(root->fs_info)) {
-			printk(KERN_DEBUG "btrfs: defrag_root cancelled\n");
+			pr_debug("BTRFS: defrag_root cancelled\n");
 			ret = -EAGAIN;
 			break;
 		}
@@ -1981,7 +1981,7 @@
 	list_del_init(&root->root_list);
 	spin_unlock(&fs_info->trans_lock);
 
-	pr_debug("btrfs: cleaner removing %llu\n", root->objectid);
+	pr_debug("BTRFS: cleaner removing %llu\n", root->objectid);
 
 	btrfs_kill_all_delayed_nodes(root);