http: fix documentation typo
(Variable is referred to alternately as 'r' and 'req')
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/4648042
diff --git a/src/pkg/http/server.go b/src/pkg/http/server.go
index 2f545f7..ac5487f 100644
--- a/src/pkg/http/server.go
+++ b/src/pkg/http/server.go
@@ -570,7 +570,7 @@
// Handler object that calls f.
type HandlerFunc func(ResponseWriter, *Request)
-// ServeHTTP calls f(w, req).
+// ServeHTTP calls f(w, r).
func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
f(w, r)
}