Bug#805353: cryptsetup-bin: filesystem type argument -t does not support btrfs (due to path checking)

[Jonathan Dowland]

Package: cryptsetup-bin
Version: 2:1.6.6-5
Severity: normal

luksformat -t btrfs ... does not work (invalid filesystem) because the code 
looks
for /sbin/mkfs.$fs or /usr/sbin/mkfs.$fs, but mkfs.btrfs is in /bin.