RE: crc32 cleanups

[Jeff Garzik]

* Still need init_crc32:
  8139too, au1000_eth, fealnx, smc91c92_cs, xircom_tulip_cb, smc9194,
  via-rhine, winbond-840, 

* lib/uuid.o needs to be in lib/Makefile's export-objs

* in init/cleanup_crc32, don't hold spinlock during kmalloc/kfree.
  Check out other refcounting schemes in the various fs/*.c files.

* Add a Config.in entry, so that people can manually select to compile
  crc32.o as a module.  This takes care of the 3rd party module case,
  the module that might for example have been built some time
  after the kernel itself was built.