Small typos in Hot Standby docs

Here's a patch:

diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
index 6750db8..1276c39 100644
*** a/doc/src/sgml/backup.sgml
--- b/doc/src/sgml/backup.sgml
*************** if (!triggered)
*** 2018,2024 ****
<itemizedlist>
<listitem>
<para>
! Data Definition Language (DML) - INSERT, UPDATE, DELETE, COPY
FROM, TRUNCATE.
Note that there are no allowed actions that result in a trigger
being executed during recovery.
</para>
--- 2018,2024 ----
<itemizedlist>
<listitem>
<para>
! Data Manipulation Language (DML) - INSERT, UPDATE, DELETE,
COPY FROM, TRUNCATE.
Note that there are no allowed actions that result in a trigger
being executed during recovery.
</para>
*************** if (!triggered)
*** 2164,2170 ****
<listitem>
<para>
Dropping tablespaces on the primary while standby queries are using
! those tablespace for temporary work files (work_mem overflow)
</para>
</listitem>
<listitem>
--- 2164,2170 ----
<listitem>
<para>
Dropping tablespaces on the primary while standby queries are using
! those tablespaces for temporary work files (work_mem overflow)
</para>
</listitem>
<listitem>