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

Declare functions lustre_swab_llog_id and lustre_swab_ll_fid 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>