orangefs: replace LOG2 function with ilog2 kernel helper.

    Signed-off-by: Mike Marshall <hubcap@omnibond.com>
    orangefs: prettify acl.c

    Prettified acl.c to conform to linux coding style. Includes several
    related aesthetic changes to some other source files,
    including ordering of some function pointer structures to reflect
    include/linux/fs.h and fixing some comments.

    Signed-off-by: Mike Marshall <hubcap@omnibond.com>