Set m.raw in encryptedExtensionsMsg.

Otherwise adding it to the handshake hash doesn't work right.

Change-Id: I2fabae72e8b088a5df26bbeac946f19144d58733
Reviewed-on: https://boringssl-review.googlesource.com/8762
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

ssl/test/runner/handshake_messages.go

@@ -865,6 +865,7 @@ func (m *encryptedExtensionsMsg) marshal() []byte {
 }
 
 func (m *encryptedExtensionsMsg) unmarshal(data []byte) bool {
+	m.raw = data
 	if len(data) < 6 {
 		return false
 	}