Staging: lustre: ptlrpc: pack_generic: Declare local functions as static

Declare lustre_swab_ldlm_resource_desc, lustre_swab_obdo,
lustre_swab_ldlm_res_id, lustre_swab_ldlm_policy_data as static since
they are used only in this particular file. Also remove the corresponding
declarations from header file.

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>