staging: lustre: replace simple cases of LIBCFS_ALLOC with kzalloc.

All usages of the form
  LIBCFS_ALLOC(variable, sizeof(variable))
or
  LIBCFS_ALLOC(variable, sizeof(variable's-type))

are changed to
  variable = kzalloc(sizeof(...), GFP_NOFS);

Similarly, all
   LIBCFS_FREE(variable, sizeof(variable))
become
   kfree(variable);

None of these need the vmalloc option, or any of the other minor
benefits of LIBCFS_ALLOC().

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>