linux-phytec-ti

raid5: remove raid5_build_block

Now raid5_build_block is just called to set the
sector of r5dev, raid5_compute_blocknr can be
used directly for the purpose.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>