powerpc: Remove redundant sysfs_remove_file calls for cache info

When removing a directory, the sysfs core takes care of removing files
in the directory (see sysfs_remove_dir()).  So when we are about to
delete a kobject (and thus cause its sysfs directory to be removed),
we don't have to explicitly remove the files attached to it, although
it's harmless to do so.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>