FIX: mb->sector should be 4KB aliged. calc_cache_alignment() needs in
rebuild_rambuf()

- without this patch, ruby compile test in dmts doesn't work for type 1

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
mb_idx_inseg returns u8 not u32

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
space fix in rebuild_rambuf(): 1  + xx -> 1 + xx

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
add (u64) explicit cast to the argument of cpu_to_le64(sector)

- dm-crypt does like this.

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
the comment of init_devices is not the order of in-code

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
switch left-right: fix value in the context should be right-hand

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
remove WQ_NON_REENTRANT flag

lastest wq is all reentrant. there is no need to explicitly flag it.
the flag is almost deprecated (will be deleted?)

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
rename: plog_buf -> plog_seg_buf

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
rename read_plog -> read_plog_seg

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
rebuild_rambuf: rename cur -> cur_plog_buf

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
explicit naming: actual, expected instead of checksum1, 2
in apply_valid_segments()

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>
Merge branch 'feature/refactor' into develop