Minor glossary tweaks

Add "(process)" qualifier to two terms, remove self-reference in one
term.

Author: Jürgen Purtz <juergen@purtz.de>
Discussion: https://postgr.es/m/95f90a5d-7692-701d-2c0c-0c88eb5cea7d@purtz.de

doc/src/sgml/glossary.sgml

@@ -108,7 +108,7 @@
   </glossentry>
 
   <glossentry id="glossary-autovacuum">
-   <glossterm>Autovacuum</glossterm>
+   <glossterm>Autovacuum (process)</glossterm>
    <glossdef>
     <para>
      A set of background processes that routinely perform
@@ -855,8 +855,7 @@
    <glossterm>Logger (process)</glossterm>
    <glossdef>
     <para>
-     If activated, the
-     <glossterm linkend="glossary-logger">Logger</glossterm> process
+     If activated, the process
      writes information about database events into the current
      <glossterm linkend="glossary-log-file">log file</glossterm>.
      When reaching certain time- or
@@ -1486,7 +1485,7 @@
   </glossentry>
 
   <glossentry id="glossary-stats-collector">
-   <glossterm>Stats collector</glossterm>
+   <glossterm>Stats collector (process)</glossterm>
    <glossdef>
     <para>
      This process collects statistical information about the