xfs: clean up unused codes at xfs_bulkstat()

There are some unused codes at xfs_bulkstat():

- Variable bp is defined to point to the on-disk inode cluster
  buffer, but it proved to be of no practical help.

- We process the chunks of good inodes which were fetched by iterating
  btree records from an AG.  When processing inodes from each chunk,
  the code recomputing agbno if run into the first inode of a cluster,
  however, the agbno is not being used thereafter.

This patch tries to clean up those things.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_itable.c

@@ -221,7 +221,6 @@ xfs_bulkstat(
 	char			__user *ubufp;	/* pointer into user's buffer */
 	int			ubelem;	/* spaces used in user's buffer */
 	int			ubused;	/* bytes used by formatter */
-	xfs_buf_t		*bp;	/* ptr to on-disk inode cluster buf */
 
 	/*
 	 * Get the last inode value, see if there's nothing to do.
@@ -263,7 +262,6 @@ xfs_bulkstat(
 	rval = 0;
 	while (XFS_BULKSTAT_UBLEFT(ubleft) && agno < mp->m_sb.sb_agcount) {
 		cond_resched();
-		bp = NULL;
 		error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
 		if (error) {
 			/*
@@ -436,27 +434,7 @@ xfs_bulkstat(
 				irbp->ir_freecount < XFS_INODES_PER_CHUNK;
 			     chunkidx++, clustidx++, agino++) {
 				ASSERT(chunkidx < XFS_INODES_PER_CHUNK);
-				/*
-				 * Recompute agbno if this is the
-				 * first inode of the cluster.
-				 *
-				 * Careful with clustidx.   There can be
-				 * multiple clusters per chunk, a single
-				 * cluster per chunk or a cluster that has
-				 * inodes represented from several different
-				 * chunks (if blocksize is large).
-				 *
-				 * Because of this, the starting clustidx is
-				 * initialized to zero in this loop but must
-				 * later be reset after reading in the cluster
-				 * buffer.
-				 */
-				if ((chunkidx & (nicluster - 1)) == 0) {
-					agbno = XFS_AGINO_TO_AGBNO(mp,
-							irbp->ir_startino) +
-						((chunkidx & nimask) >>
-						 mp->m_sb.sb_inopblog);
-				}
+
 				ino = XFS_AGINO_TO_INO(mp, agno, agino);
 				/*
 				 * Skip if this inode is free.
@@ -502,10 +480,6 @@ xfs_bulkstat(
 
 			cond_resched();
 		}
-
-		if (bp)
-			xfs_buf_relse(bp);
-
 		/*
 		 * Set up for the next loop iteration.
 		 */