doc/go1.16: revamp vet check for asn1.Unamrshal section

doc/go1.16.html

@@ -381,21 +381,11 @@ <h4 id="vet-frame-pointer">New warning for frame pointer</h4>
 <h4 id="vet-asn1-unmarshal">New warning for asn1.Unmarshal</h4>
 
 <p><!-- CL 243397 -->
-  The vet tool now warns about invalid calls of
+  The vet tool now warns about incorrectly passing a non-pointer or nil argument to
   <a href="/pkg/encoding/asn1/#Unmarshal"><code>asn1.Unmarshal</code></a>.
-  If you pass non-pointer or nil argument to
-  <a href="/pkg/encoding/asn1/#Unmarshal"><code>asn1.Unmarshal</code></a>,
-  the vet tool will report it.
-</p>
-
-<p>
-  The vet tool already has been checking invalid <code>Unmarshal</code> and
-  <code>Decode</code> calls of other encoding packages such as
-  <a href="/pkg/encoding/json"><code>encoding/json</code></a>,
-  <a href="/pkg/encoding/xml"><code>encoding/xml</code></a>.
-  This release makes the vet tool check
-  <a href="/pkg/encoding/asn1"><code>encoding/asn1</code></a>'s one
-  as well.
+  This is like the existing checks for
+  <a href="/pkg/encoding/json/#Unmarshal"><code>encoding/json.Unmarshal</code></a>
+  and <a href="/pkg/encoding/xml/#Unmarshal"><code>encoding/xml.Unmarshal</code></a>.
 </p>
 
 <h2 id="runtime">Runtime</h2>