key->type is u8, not u64.

fs/btrfs/ioctl.c: In function 'copy_to_sk':
fs/btrfs/ioctl.c:1024: warning: comparison is always true due to limited range of data type
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>