GFS2: Move i_size from gfs2_dinode_host and rename it to i_disksize

This patch moved the i_size field from the gfs2_dinode_host and
following the ext3 convention renames it i_disksize.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 2d90fb2..bdad0df 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -501,7 +501,7 @@
 	for (rgrps = 0;; rgrps++) {
 		loff_t pos = rgrps * sizeof(struct gfs2_rindex);
 
-		if (pos + sizeof(struct gfs2_rindex) >= ip->i_di.di_size)
+		if (pos + sizeof(struct gfs2_rindex) >= ip->i_disksize)
 			break;
 		error = gfs2_internal_read(ip, &ra_state, buf, &pos,
 					   sizeof(struct gfs2_rindex));
@@ -590,7 +590,7 @@
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 	struct inode *inode = &ip->i_inode;
 	struct file_ra_state ra_state;
-	u64 rgrp_count = ip->i_di.di_size;
+	u64 rgrp_count = ip->i_disksize;
 	int error;
 
 	if (do_div(rgrp_count, sizeof(struct gfs2_rindex))) {
@@ -634,7 +634,7 @@
 	for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) {
 		/* Ignore partials */
 		if ((sdp->sd_rgrps + 1) * sizeof(struct gfs2_rindex) >
-		    ip->i_di.di_size)
+		    ip->i_disksize)
 			break;
 		error = read_rindex_entry(ip, &ra_state);
 		if (error) {