proc_close: "waits", not "closes". Also grammar fix in Returns.

The function waits (waitpid) for a process to terminate, it does not do any closing. The description is a little misleading.

Author: SinusPi

reference/exec/functions/proc-close.xml

@@ -4,7 +4,7 @@
 <refentry xml:id='function.proc-close' xmlns="http://docbook.org/ns/docbook">
  <refnamediv>
   <refname>proc_close</refname>
-  <refpurpose>Close a process opened by <function>proc_open</function> and return the exit code of that process</refpurpose>
+  <refpurpose>Wait for a process opened by <function>proc_open</function> to close and return the exit code of that process</refpurpose>
  </refnamediv>
 
  <refsect1 role="description">
@@ -46,7 +46,7 @@
   &reftitle.returnvalues;
   <para>
    Returns the termination status of the process that was run. In case of 
-   an error then <literal>-1</literal> is returned.
+   an error <literal>-1</literal> is returned.
   </para>
   &note.sigchild;
  </refsect1>