Bug#365747: crypt? nodes also needed

[David Härdeman <david@2gen.com>]

Note that if the initramfs hook is supposed to work (i.e. generate an 
initramfs image with the proper crypto modules), the /dev/mapper/crypt? 
nodes created by partman-crypto during the installation probably also 
need to be copied to /target/dev/mapper/

Re,
David