GFS2: introduce bi_blocks for optimization

This patch introduces a new field in the bitmap structure called
bi_blocks. Its purpose is to save us from constantly multiplying
bi_len by the constant GFS2_NBBY. It also paves the way for more
optimization in a future patch.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 26aabd7..f1a3243 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -71,6 +71,7 @@
 	u32 bi_offset;
 	u32 bi_start;
 	u32 bi_len;
+	u32 bi_blocks;
 };
 
 struct gfs2_rgrpd {