firmware: add debug facility to emulate disabling sysfs fallback

One can build a kernel without CONFIG_FW_LOADER_USER_HELPER being
enabled, but testing it requires a unique kernel configuration most
folks do not enable. This makes it hard to test.

Provide a debugfs facility to enable us to emulate such kernels.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
3 files changed