doc: Fix some trailing whitespace

doc/src/sgml/ecpg.sgml

@@ -4788,7 +4788,7 @@ EXEC SQL WHENEVER <replaceable>condition</replaceable> <replaceable>action</repl
       <listitem>
        <para>
         Execute the C statement <literal>continue</literal>.  This should
-        only be used in loops statements.  if executed, will cause the flow 
+        only be used in loops statements.  if executed, will cause the flow
         of control to return to the top of the loop.
        </para>
       </listitem>

doc/src/sgml/ref/alter_index.sgml

@@ -134,7 +134,7 @@ ALTER INDEX ALL IN TABLESPACE <replaceable class="parameter">name</replaceable>
       subsequent <xref linkend="sql-analyze"/> operations, though can
       be used only on index columns that are defined as an expression.
       Since expressions lack a unique name, we refer to them using the
-      ordinal number of the index column. 
+      ordinal number of the index column.
       The target can be set in the range 0 to 10000; alternatively, set it
       to -1 to revert to using the system default statistics
       target (<xref linkend="guc-default-statistics-target"/>).

doc/src/sgml/ref/pgbench.sgml

@@ -948,7 +948,7 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
     <term><literal>\else</literal></term>
     <term><literal>\endif</literal></term>
     <listitem>
-     <para> 
+     <para>
       This group of commands implements nestable conditional blocks,
       similarly to <literal>psql</literal>'s <xref linkend="psql-metacommand-if"/>.
       Conditional expressions are identical to those with <literal>\set</literal>,
@@ -1415,7 +1415,7 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
    <para>
     The <literal>random</literal> function generates values using a uniform
     distribution, that is all the values are drawn within the specified
-    range with equal probability. The <literal>random_exponential</literal>, 
+    range with equal probability. The <literal>random_exponential</literal>,
     <literal>random_gaussian</literal> and <literal>random_zipfian</literal>
     functions require an additional double parameter which determines the precise
     shape of the distribution.

doc/src/sgml/runtime.sgml

@@ -2457,7 +2457,7 @@ openssl x509 -req -in server.csr -text -days 365 \
     <filename>server.crt</filename> and <filename>server.key</filename>
     should be stored on the server, and <filename>root.crt</filename> should
     be stored on the client so the client can verify that the server's leaf
-    certificate was signed by its trusted root certificate. 
+    certificate was signed by its trusted root certificate.
     <filename>root.key</filename> should be stored offline for use in
     creating future certificates.
    </para>

doc/src/sgml/spgist.sgml

@@ -779,7 +779,7 @@ typedef struct spgLeafConsistentOut
        parent tuple; it is <literal>(Datum) 0</literal> at the root level or if the
        <function>inner_consistent</function> function did not provide a value at the
        parent level. <structfield>reconstructedValue</structfield> is always of
-       <structname>spgConfigOut</structname>.<structfield>leafType</structfield> type. 
+       <structname>spgConfigOut</structname>.<structfield>leafType</structfield> type.
        <structfield>traversalValue</structfield> is a pointer to any traverse data
        passed down from the previous call of <function>inner_consistent</function>
        on the parent index tuple, or NULL at the root level.
@@ -817,7 +817,7 @@ typedef struct spgLeafConsistentOut
      <term><function>Datum compress(Datum in)</function></term>
      <listitem>
       <para>
-       Converts the data item into a format suitable for physical storage in 
+       Converts the data item into a format suitable for physical storage in
        a leaf tuple of index page.  It accepts
        <structname>spgConfigIn</structname>.<structfield>attType</structfield>
        value and return