reorder struct module to save space on 64 bit builds.
saves 1 cacheline_size  (128 on default x86_64 & 64 on AMD
Opteron/athlon) when CONFIG_MODULE_UNLOAD=y.
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>