sysfs: remove exports of sysfs_*change_owner()

sysfs: remove exports of sysfs_*change_owner()

Both sysfs_change_owner() and sysfs_file_change_owner() are exported to
modules, but there are no in-kernel module users, so remove the exports
so that crazy out-of-tree drivers don't get the impression that it is
safe to call these functions at all.

Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reported-by: Lee Jones <lee@kernel.org>
Reviewed-by: Lee Jones <lee@kernel.org>
Link: https://patch.msgid.link/2026020541-energize-graduate-981a@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>