doc: fix typo in Go for C++ programmers

R=iant
CC=golang-dev
https://golang.org/cl/5555062

doc/go_for_cpp_programmers.html

@@ -225,7 +225,7 @@ f(v9.i, p9.i)
 </pre>
 
 <p>
-Go does not require parentheses around the condition of a <code>if</code>
+Go does not require parentheses around the condition of an <code>if</code>
 statement, or the expressions of a <code>for</code> statement, or the value of a
 <code>switch</code> statement.  On the other hand, it does require curly braces
 around the body of an <code>if</code> or <code>for</code> statement.
@@ -538,7 +538,7 @@ func f2() {
 
 <p>
 The <code>set</code> method is effectively inherited from
-<code>myChildType</code>, because
+<code>myType</code>, because
 methods associated with the anonymous field are promoted to become methods
 of the enclosing type.  In this case, because <code>myChildType</code> has an
 anonymous field of type <code>myType</code>, the methods of