mgmt: fix InternalFace::processInterest crash when Interest is gone

Interest may be satisfied by Notification and be removed from PIT
between sendInterest and processInterest.

refs #1452

Change-Id: I0c3e05c34f0d8607d96dcfd156a3e87c1ecb26f2
diff --git a/tests/mgmt/fib-manager.cpp b/tests/mgmt/fib-manager.cpp
index f2d059a..0e2e8c0 100644
--- a/tests/mgmt/fib-manager.cpp
+++ b/tests/mgmt/fib-manager.cpp
@@ -239,13 +239,13 @@
 {
   shared_ptr<InternalFace> face = getInternalFace();
 
-  Interest command("/localhost/nfd/fib");
+  shared_ptr<Interest> command = makeInterest("/localhost/nfd/fib");
 
   face->onReceiveData +=
     bind(&FibManagerFixture::validateControlResponse, this,  _1,
-         command.getName(), 400, "Malformed command");
+         command->getName(), 400, "Malformed command");
 
-  face->sendInterest(command);
+  face->sendInterest(*command);
   g_io.run_one();
 
   BOOST_REQUIRE(didCallbackFire());