strtobool() is a wrapper around kstrtobool() that has been added for
backward compatibility.

There is no reason to use the old API, so use kstrtobool() directly.

Related: ef951599 ("lib: move strtobool() to kstrtobool()")

Link: https://lore.kernel.org/r/20210915230127.2495723-3-kw@linux.comSigned-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>