modprobe: Fix holders removal

modprobe: Fix holders removal

The idea behind --remove-dependencies was to remove other modules that
depend on the current module being removed. It's the reverse
dependency list, not the dependency list of the current module: that
never works since the current module would still hold a ref on it.

Fix it by replacing the call to kmod_module_get_dependencies() with
kmod_module_get_holders() when using that option. Also try to cleanup
the confusion by renaming the option to --remove-holders: "holder" is
the name used in sysfs and by libkmod to refer to a "live" reverse
dependency like what we are interested in.

Before:
	./tools/modprobe -D -r --remove-dependencies video
	rmmod video

After:
	./tools/modprobe -D -r --remove-holders video
	rmmod i915
	rmmod thinkpad_acpi
	rmmod video

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>