GFS2: Copy gfs2_trans_add_bh into new data/meta functions

This patch copies the body of gfs2_trans_add_bh into the two newly
added gfs2_trans_add_data and gfs2_trans_add_meta functions. We can
then move the .lo_add functions from lops.c into trans.c and call
them directly.

As a result of this, we no longer need to use the .lo_add functions
at all, so that is removed from the log operations structure.

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

fs/gfs2/incore.h

@@ -52,7 +52,6 @@ struct gfs2_log_header_host {
  */
 
 struct gfs2_log_operations {
-	void (*lo_add) (struct gfs2_sbd *sdp, struct gfs2_bufdata *bd);
 	void (*lo_before_commit) (struct gfs2_sbd *sdp);
 	void (*lo_after_commit) (struct gfs2_sbd *sdp, struct gfs2_ail *ai);
 	void (*lo_before_scan) (struct gfs2_jdesc *jd,