Staging: lustre: obdclass: lprocfs_status: Declare local functions as static

Declare lustre_attr_show and lustre_attr_store as static
since they are used only in this particular file. Also remove them from
corresponding header files.

Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>