net/http: fix typo in comment in main_test

Change-Id: I22d4b5a0d5c146a65d4ef77a32e23f7780ba1d95
Reviewed-on: https://go-review.googlesource.com/22684
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/net/http/main_test.go

@@ -123,7 +123,7 @@ func afterTest(t testing.TB) {
 
 // waitCondition reports whether fn eventually returned true,
 // checking immediately and then every checkEvery amount,
-// until waitFor has elpased, at which point it returns false.
+// until waitFor has elapsed, at which point it returns false.
 func waitCondition(waitFor, checkEvery time.Duration, fn func() bool) bool {
 	deadline := time.Now().Add(waitFor)
 	for time.Now().Before(deadline) {