scd: Fix an action after card removal.

* scd/command.c (update_card_removed): Call apdu_close_reader here.

This is update of the commit 8fe81055762d9c9e6f03fb7853a985c94ef73ac3
It is better apdu_close_reader is called in update_card_removed.

The commit 1598a4476466822e7e9c757ac471089d3db4b545 introduced a
regression, it doesn't close the reader after removal of the card, while
the code before the commit call apdu_close_reader in do_reset.
So, this fix.

• GnuPG-bug-id: T2449
• Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>