doc/go1.5.html: fix typo

Change-Id: I8bbdf6c769e089fca8458166dffff5aea0f74675
Reviewed-on: https://go-review.googlesource.com/12196Reviewed-by: Andrew Gerrand <adg@golang.org>

doc/go1.5.html

@@ -214,7 +214,7 @@ For details, see the <a href="https://golang.org/s/go15bootstrap">design documen
 <h2 id="ports">Ports</h2>
 
 <p>
-Due mostly to the industry's move away the 32-bit x86 architecture,
+Due mostly to the industry's move away from the 32-bit x86 architecture,
 the set of binary downloads provided is reduced in 1.5.
 A distribution for the OS X operating system is provided only for the
 <code>amd64</code> architecture, not <code>386</code>.