ext4: don't open-code ERR_CAST

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/ext4/ialloc.c

@@ -1216,7 +1216,7 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
 	bitmap_bh = ext4_read_inode_bitmap(sb, block_group);
 	if (IS_ERR(bitmap_bh))
-		return (struct inode *) bitmap_bh;
+		return ERR_CAST(bitmap_bh);
 
 	/* Having the inode bit set should be a 100% indicator that this
 	 * is a valid orphan (no e2fsck run on fs).  Orphans also include

fs/ext4/namei.c

@@ -1556,7 +1556,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
 
 	bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL);
 	if (IS_ERR(bh))
-		return (struct dentry *) bh;
+		return ERR_CAST(bh);
 	inode = NULL;
 	if (bh) {
 		__u32 ino = le32_to_cpu(de->inode);
@@ -1600,7 +1600,7 @@ struct dentry *ext4_get_parent(struct dentry *child)
 
 	bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL);
 	if (IS_ERR(bh))
-		return (struct dentry *) bh;
+		return ERR_CAST(bh);
 	if (!bh)
 		return ERR_PTR(-ENOENT);
 	ino = le32_to_cpu(de->inode);