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

Declare llog_cat_id2handle and llog_cat_process_or_fork as static
since they are used only in this particular file. Also remove the
corresponding declarations from header files.

Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>