doc: fix typo in FAQ

Change-Id: I956d6d1dbf8516cb65eb3a0686a3b0584b4a6840
GitHub-Last-Rev: 1c928f3c67eceae424cbcd6b0935605a78728604
GitHub-Pull-Request: golang/go#28991
Reviewed-on: https://go-review.googlesource.com/c/151324Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

doc/go_faq.html

@@ -1769,7 +1769,7 @@ while that of the corresponding pointer
 type <code>*T</code> consists of all methods with receiver <code>*T</code> or
 <code>T</code>.
 That means the method set of <code>*T</code>
-includes that of <code>T</code>),
+includes that of <code>T</code>,
 but not the reverse.
 </p>