test: don't close CRT fd handed off to uv_pipe_t

After 4ed29c2498 got fixed, when a CRT fd
is handed off to a pipe handle using uv_pipe_open libuv will close it
properly, so it's an error to do so ourselves.

PR-URL: https://github.com/libuv/libuv/pull/992
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

test/test-pipe-getsockname.c

@@ -255,7 +255,6 @@ TEST_IMPL(pipe_getsockname_blocking) {
 
   ASSERT(pipe_close_cb_called == 1);
 
-  _close(readfd);
   CloseHandle(writeh);
 #endif