doc: fix typo in faq

Change-Id: Id2cfa63d4c749503f729097654d7cbd2b252f192
Reviewed-on: https://go-review.googlesource.com/11660Reviewed-by: Andrew Gerrand <adg@golang.org>

doc/go_faq.html

@@ -1321,7 +1321,7 @@ The number of CPUs available simultaneously to executing goroutines is
 controlled by the <code>GOMAXPROCS</code> shell environment variable.
 In earlier releases of Go, the default value was 1, but as of Go 1.5 the default
 value is the number of cores available.
-Therefore programs compiled afer 1.5 should demonstrate parallel execution
+Therefore programs compiled after 1.5 should demonstrate parallel execution
 of multiple goroutines.
 To change the behavior, set the environment variable or use the similarly-named
 <a href="/pkg/runtime/#GOMAXPROCS">function</a>