Btrfs: remove outdated comment in btrfs_ioctl_resize()

In Li Zefan's commit dae7b665,
a combination call of kmalloc() and copy_from_user() is replaced by
memdup_user(). So btrfs_ioctl_resize() doesn't use GFP_NOFS any more.
Signed-off-by: NLi Hong <lihong.hi@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/ioctl.c

@@ -437,10 +437,6 @@ static int btrfs_defrag_file(struct file *file)
 	return 0;
 }
 
-/*
- * Called inside transaction, so use GFP_NOFS
- */
-
 static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
 {
 	u64 new_size;