Fix code example and add missing periods in titles

Author: rodrigoprimo

WordPress/Docs/DB/RestrictedFunctionsStandard.xml

@@ -24,7 +24,7 @@ $results = <em>mysqli_query</em>(
         </code>
     </code_comparison>
     <code_comparison>
-        <code title="Valid: Using WordPress functions to insert a post">
+        <code title="Valid: Using WordPress functions to insert a post.">
         <![CDATA[
 <em>wp_insert_post</em>(
     array( 'post_title' => 'Title' )
@@ -34,13 +34,13 @@ $results = <em>mysqli_query</em>(
 
 global $wpdb;
 <em>$wpdb->insert</em>(
-    "{$wpdb->prefix}_posts",
+    $wpdb->posts,
     array( 'post_title' => 'Title' ),
     array( '%s' )
 );
         ]]>
         </code>
-        <code title="Invalid: Using MySQLi library to insert a post">
+        <code title="Invalid: Using MySQLi library to insert a post.">
         <![CDATA[
 <em>mysqli_query</em>(
     $mysql,