doc/go1.5: fix hyperlink for runtime/trace

Missed in CL 13074.

Change-Id: Ic0600341abbc423cd8d7b2201bf50e3b0bf398a7
Reviewed-on: https://go-review.googlesource.com/13167Reviewed-by: Ian Lance Taylor <iant@golang.org>

doc/go1.5.html

@@ -1227,7 +1227,7 @@ adds new <a href="/pkg/os/signal/#Ignore"><code>Ignore</code></a> and
 
 <li>
 The <a href="/pkg/runtime/"><code>runtime</code></a>,
-<a href="/pkg/runtime/pprof/"><code>runtime/trace</code></a>,
+<a href="/pkg/runtime/trace/"><code>runtime/trace</code></a>,
 and <a href="/pkg/net/http/pprof/"><code>net/http/pprof</code></a> packages
 each have new functions to support the tracing facilities described above:
 <a href="/pkg/runtime/#ReadTrace"><code>ReadTrace</code></a>,