We create a file in orphan dir for reflink so that if there
is any error, we don't create any wrong dentry in the dir.
But actually the file in orphan dir should be i_nlink = 0
so that it can be replayed and freed successfully.

This patch first set i_nlink to 0 when creating the file in
orphan dir and then set it to 1(reflink now only works for
regular file) when we move it to the dest dir.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>