ubifs: Fix xattr_names length in exit paths

When the operation fails we also have to undo the changes
we made to ->xattr_names. Otherwise listxattr() will report
wrong lengths.

Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/xattr.c

@@ -172,6 +172,7 @@ static int create_xattr(struct ubifs_info *c, struct inode *host,
 	host_ui->xattr_cnt -= 1;
 	host_ui->xattr_size -= CALC_DENT_SIZE(nm->len);
 	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
+	host_ui->xattr_names -= nm->len;
 	mutex_unlock(&host_ui->ui_mutex);
 out_free:
 	make_bad_inode(inode);
@@ -478,6 +479,7 @@ static int remove_xattr(struct ubifs_info *c, struct inode *host,
 	host_ui->xattr_cnt += 1;
 	host_ui->xattr_size += CALC_DENT_SIZE(nm->len);
 	host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
+	host_ui->xattr_names += nm->len;
 	mutex_unlock(&host_ui->ui_mutex);
 	ubifs_release_budget(c, &req);
 	make_bad_inode(inode);