Fix syntax descriptions for replication commands in logicaldecoding.sgml

Patch-by: Oleksandr Shulgin
Reviewed-by: Craig Ringer and Fujii Masao
Backpatch-through: 9.4 where logical decoding was introduced

doc/src/sgml/logicaldecoding.sgml

@@ -280,7 +280,7 @@ $ pg_recvlogical -d postgres --slot test --drop-slot
     The commands
     <itemizedlist>
      <listitem>
-      <para><literal>CREATE_REPLICATION_SLOT <replaceable>slot_name</replaceable> LOGICAL <replaceable>options</replaceable></literal></para>
+      <para><literal>CREATE_REPLICATION_SLOT <replaceable>slot_name</replaceable> LOGICAL <replaceable>output_plugin</replaceable></literal></para>
      </listitem>
 
      <listitem>
@@ -288,7 +288,7 @@ $ pg_recvlogical -d postgres --slot test --drop-slot
      </listitem>
 
      <listitem>
-      <para><literal>START_REPLICATION SLOT <replaceable>slot_name</replaceable> LOGICAL <replaceable>options</replaceable></literal></para>
+      <para><literal>START_REPLICATION SLOT <replaceable>slot_name</replaceable> LOGICAL ...</literal></para>
      </listitem>
     </itemizedlist>
     are used to create, drop, and stream changes from a replication