net/http: skip TestTransportClosesBodyOnError on Plan 9

LGTM=rsc
R=bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/87800044

src/pkg/net/http/transport_test.go

diff --git a/src/pkg/net/http/transport_test.go b/src/pkg/net/http/transport_test.go
index 3e6235a..17c9aae 100644
--- a/src/pkg/net/http/transport_test.go
+++ b/src/pkg/net/http/transport_test.go
@@ -2040,6 +2040,9 @@
 
 // Issue 6981
 func TestTransportClosesBodyOnError(t *testing.T) {
+	if runtime.GOOS == "plan9" {
+		t.Skip("skipping test; see http://golang.org/issue/7782")
+	}
 	defer afterTest(t)
 	readBody := make(chan error, 1)
 	ts := httptest.NewServer(HandlerFunc(func(w ResponseWriter, r *Request) {