From: Andrej Manduch <amanduch@redhat.com>
in case sudo is not able to authentificate user `sudo whoami` doesn't
returrn anything and [ $(sudo whoami) != "root" ] will trigger error.
Reproducer of previous behaviour:
./arm-image-installer
[sudo] password for burlak:
sudo: 3 incorrect password attempts
./arm-image-installer: line 42: [: !=: unary operator expected
Usage: arm-image-installer <options>
Fixed behaviour:
./arm-image-installer
[sudo] password for burlak:
sudo: 3 incorrect password attempts
Error: This script requires 'sudo' privileges in order to write to disk
& mount media.
Signed-off-by: Andrej Manduch <amanduch@gmail.com>
Tested-by: Peter Robinson <pbrobinson@fedoraproject.org>