ocfs2: Track local alloc bits internally

Do this instead of tracking absolute local alloc size. This avoids
needless re-calculatiion of bits from bytes in localalloc.c. Additionally,
the value is now in a more natural unit for internal file system bitmap
work.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>

diff --cc fs/ocfs2/localalloc.c
Simple merge

diff --cc fs/ocfs2/ocfs2.h
Simple merge

diff --cc fs/ocfs2/super.c
Simple merge