The definition of the `unittest_fptr` function pointer type has the wrong function return type `void *` instead of `void`. The problem is hidden by a bunch of unnecessary type-casts. Fix the type definition and remove the type-casts. Cc: Spencer E. Olson <olsonse@umich.edu> Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20210407140142.447250-6-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>