In 29a00c41 an override was added, but commandline variables have
higher precedence than Makefile variables, so the override was not
effective for commandline variables.
While at it, duplicate for libudev.
In 29a00c41 an override was added, but commandline variables have
higher precedence than Makefile variables, so the override was not
effective for commandline variables.
While at it, duplicate for libudev.