Fix typos in documentation and for one wait event

These have been found while cross-checking for the use of unique words
in the documentation, and a wait event was not getting generated in a way
consistent to what the documentation provided.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/9b5a3a85-899a-ae62-dbab-1e7943aa5ab1@gmail.com

doc/src/sgml/file-fdw.sgml

@@ -187,7 +187,7 @@
  <para>
   Changing table-level options requires being a superuser or having the privileges
   of the default role <literal>pg_read_server_files</literal> (to use a filename) or
-  the default role <literal>pg_execute_server_programs</literal> (to use a program),
+  the default role <literal>pg_execute_server_program</literal> (to use a program),
   for security reasons: only certain users should be able to control which file is
   read or which program is run.  In principle regular users could be allowed to
   change the other options, but that's not supported at present.

doc/src/sgml/func.sgml

@@ -16399,7 +16399,7 @@ SET search_path TO <replaceable>schema</replaceable> <optional>, <replaceable>sc
     optional parameter. The return value is <literal>NULL</literal> when the
     log format requested is not a configured
     <xref linkend="guc-log-destination"/>.  The
-    <function>pg_current_logfiles</function> reflects the contents of the
+    <function>pg_current_logfile</function> reflects the contents of the
     <filename>current_logfiles</filename> file.
    </para>
 

doc/src/sgml/libpq.sgml

@@ -6205,7 +6205,7 @@ char *PQencryptPasswordConn(PGconn *conn, const char *passwd, const char *user,
 char *PQencryptPassword(const char *passwd, const char *user);
 </synopsis>
       <function>PQencryptPassword</function> is an older, deprecated version of
-      <function>PQencryptPasswodConn</function>. The difference is that
+      <function>PQencryptPasswordConn</function>. The difference is that
       <function>PQencryptPassword</function> does not
       require a connection object, and <literal>md5</literal> is always used as the
       encryption algorithm.

doc/src/sgml/ref/pg_dump.sgml

@@ -1290,7 +1290,7 @@ CREATE DATABASE foo WITH TEMPLATE template0;
   <para>
    When dumping logical replication subscriptions,
    <application>pg_dump</application> will generate <command>CREATE
-   SUBSCRIPTION</command> commands that use the <literal>NOCONNECT</literal>
+   SUBSCRIPTION</command> commands that use the <literal>connect = false</literal>
    option, so that restoring the subscription does not make remote connections
    for creating a replication slot or for initial table copy.  That way, the
    dump can be restored without requiring network access to the remote

src/backend/postmaster/pgstat.c

@@ -3799,7 +3799,7 @@ pgstat_get_wait_io(WaitEventIO w)
 			event_name = "LockFileCreateSync";
 			break;
 		case WAIT_EVENT_LOCK_FILE_CREATE_WRITE:
-			event_name = "LockFileCreateWRITE";
+			event_name = "LockFileCreateWrite";
 			break;
 		case WAIT_EVENT_LOCK_FILE_RECHECKDATADIR_READ:
 			event_name = "LockFileReCheckDataDirRead";