- fix typos

PR:		docs/155366
Submitted by:	eadler

en_US.ISO8859-1/articles/committers-guide/article.sgml

@@ -1762,7 +1762,7 @@ docs:Documentation Bug:freebsd-doc:</programlisting>
 	<listitem>
 	  <para>A short guide about fixes which are committed to the &os;
 	    source tree after being detected by &coverity.prevent; and
-	    analyzed by an &os; developer.</para>
+	    analyzed by a &os; developer.</para>
 	</listitem>
       </varlistentry>
     </variablelist>

en_US.ISO8859-1/books/handbook/jails/chapter.sgml

@@ -119,7 +119,7 @@
         <term>hosted (system, process, user, etc.)</term>
         <listitem>
 	  <para>A process, user or other entity, whose access to resources is
-	    restricted by an &os; jail.</para>
+	    restricted by a &os; jail.</para>
 	</listitem>
       </varlistentry>
     </variablelist>

en_US.ISO8859-1/books/handbook/security/chapter.sgml

@@ -608,7 +608,7 @@
 	and the value of the <varname>kern_securelevel</varname> variable to
 	the desired secure level.</para>
 
-      <para>The default secure level of an &os; system right after the startup
+      <para>The default secure level of a &os; system right after the startup
 	scripts are done is -1.  This is called <quote>insecure mode</quote>
 	because immutable file flags may be turned off, all devices may be
 	read from or written to, and so on.</para>