libkmod: silence unused param warnings for kmod_file_load_*() stubs

libkmod: silence unused param warnings for kmod_file_load_*() stubs

When building without compression, the respective load functions are
static inline header stubs. In which case the struct kmod_file *file is
always unused and the compiler rightfully warns about it.

Not much we can do here, other than annotate them to silence the
warnings.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/361
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>