Error message needs to be proper while creating user with invalid password

[rahulmah]

At present we get generic message"Failed to create new user" while creating user with invalid password(e.g. abc, test). This need to be improved.

We should get something like - "User creation failed due to invalid password."

Tested with below latest master build:

root@witherspoon:~# cat /etc/os-release
ID="openbmc-phosphor"
NAME="Phosphor OpenBMC (Phosphor OpenBMC Project Reference Distro)"
VERSION="2.7.0-dev"
VERSION_ID="2.7.0-dev-222-g4b8d2d036"
PRETTY_NAME="Phosphor OpenBMC (Phosphor OpenBMC Project Reference Distro) 2.7.0-dev"
BUILD_ID="2.7.0-dev"
OPENBMC_TARGET_MACHINE="witherspoon"
root@witherspoon:~#