driver core: remove make_class_name declaration

make_class_name has been removed since
commit 39aba963 ("driver core: remove CONFIG_SYSFS_DEPRECATED_V2
but keep it for block devices"), so remove it.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20220909063337.1146151-1-cuigaosheng1@huawei.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>