Btrfs: fix compiler warnings

... regarding an unused function when !MIGRATION, and regarding a
printk() format string vs argument mismatch.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4875d69..5f91944 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5712,9 +5712,9 @@
 
 	if (err) {
 		printk(KERN_ERR "btrfs direct IO failed ino %lu rw %lu "
-		      "disk_bytenr %lu len %u err no %d\n",
-		      dip->inode->i_ino, bio->bi_rw, bio->bi_sector,
-		      bio->bi_size, err);
+		      "sector %#Lx len %u err no %d\n",
+		      dip->inode->i_ino, bio->bi_rw,
+		      (unsigned long long)bio->bi_sector, bio->bi_size, err);
 		dip->errors = 1;
 
 		/*