functions.sh: Add failed commands to shell history.
functions.sh: Add failed commands to shell history.

It's nice to be able to just hit the up arrow to try the command again,
especially in the case when cryptsetup fails due to invalid password
entry, and you'd like a quick extra chance at entering your 93 character
long military grade password.

Signed-off-by: Piotr Karbowski <7d031c49814378d779180c14b37fc24cb0ca09f4@gmail.com>

slashbeast/better-initramfs,jakeogh/better-initramfs,zakx/gov-initramfs