gfs2: Use IS_ERR_OR_NULL

Use IS_ERR_OR_NULL where appropriate.

(Several more places converted by Andreas.)
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/dir.c

@@ -750,7 +750,7 @@ static struct gfs2_dirent *gfs2_dirent_split_alloc(struct inode *inode,
 	struct gfs2_dirent *dent;
 	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size,
 				gfs2_dirent_find_offset, name, ptr);
-	if (!dent || IS_ERR(dent))
+	if (IS_ERR_OR_NULL(dent))
 		return dent;
 	return do_init_dirent(inode, dent, name, bh,
 			      (unsigned)(ptr - (void *)dent));
@@ -854,7 +854,7 @@ static struct gfs2_dirent *gfs2_dirent_search(struct inode *inode,
 		return ERR_PTR(error);
 	dent = gfs2_dirent_scan(inode, bh->b_data, bh->b_size, scan, name, NULL);
 got_dent:
-	if (unlikely(dent == NULL || IS_ERR(dent))) {
+	if (IS_ERR_OR_NULL(dent)) {
 		brelse(bh);
 		bh = NULL;
 	}

fs/gfs2/glock.c

@@ -681,7 +681,7 @@ static void delete_work_func(struct work_struct *work)
 		goto out;
 
 	inode = gfs2_lookup_by_inum(sdp, no_addr, NULL, GFS2_BLKST_UNLINKED);
-	if (inode && !IS_ERR(inode)) {
+	if (!IS_ERR_OR_NULL(inode)) {
 		d_prune_aliases(inode);
 		iput(inode);
 	}

fs/gfs2/inode.c

@@ -793,7 +793,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 fail_gunlock:
 	gfs2_dir_no_add(&da);
 	gfs2_glock_dq_uninit(ghs);
-	if (inode && !IS_ERR(inode)) {
+	if (!IS_ERR_OR_NULL(inode)) {
 		clear_nlink(inode);
 		if (!free_vfs_inode)
 			mark_inode_dirty(inode);

fs/gfs2/ops_fstype.c

@@ -576,7 +576,7 @@ static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 
 		INIT_WORK(&jd->jd_work, gfs2_recover_func);
 		jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1);
-		if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
+		if (IS_ERR_OR_NULL(jd->jd_inode)) {
 			if (!jd->jd_inode)
 				error = -ENOENT;
 			else