shim: don't clear environment when invoking handshaker.

Change-Id: I266bf4dfbbc9b1867fbc91d44393c3f0a6ea9391
Reviewed-on: https://boringssl-review.googlesource.com/31405
Reviewed-by: Adam Langley <agl@google.com>

ssl/test/handshake_util.cc

diff --git a/ssl/test/handshake_util.cc b/ssl/test/handshake_util.cc
index f839653..a36b41a 100644
--- a/ssl/test/handshake_util.cc
+++ b/ssl/test/handshake_util.cc
@@ -349,7 +349,7 @@
   // it to -1.
   pid_t handshaker_pid = -1;
   int ret = posix_spawn(&handshaker_pid, args[0], &actions, nullptr,
-                        args.data(), nullptr);
+                        args.data(), environ);
   if (posix_spawn_file_actions_destroy(&actions) != 0 ||
       ret != 0) {
     return false;