doc: fix typos in go1.1

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/8342044

doc/go1.1.html

@@ -291,7 +291,7 @@ The byte-order-mark change is strictly backward-compatible.
 A major addition to the tools is a <em>race detector</em>, a way to find
 bugs in programs caused by problems like concurrent changes to the same variable.
 This new facility is built into the <code>go</code> tool.
-To enable it, set the the <code>-race</code> flag when building or testing your program 
+To enable it, set the <code>-race</code> flag when building or testing your program 
 (for instance, <code>go test -race</code>).
 The race detector is documented in <a href="/doc/articles/race_detector.html">a separate article</a>.
 </p>
@@ -968,7 +968,7 @@ The <a href="/pkg/strings/"><code>strings</code></a> package has two new functio
 <a href="/pkg/strings/#TrimPrefix"><code>TrimPrefix</code></a>
 and
 <a href="/pkg/strings/#TrimSuffix"><code>TrimSuffix</code></a>
-with self-evident properties, and the the new method
+with self-evident properties, and the new method
 <a href="/pkg/strings/#Reader.WriteTo"><code>Reader.WriteTo</code></a> so the
 <a href="/pkg/strings/#Reader"><code>Reader</code></a>
 type now implements the