Drop libweave part from includes.

The extra prefix is cumbersome for packaging the library since that directory
part will contain a version number.

Change-Id: Iecaa0803185e5dd1d65d83fda79514351507b155
Reviewed-on: https://weave-review.googlesource.com/1160
Reviewed-by: Vitaly Buka <vitalybuka@google.com>
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
diff --git a/libweave/src/backoff_entry_unittest.cc b/libweave/src/backoff_entry_unittest.cc
index 5b198a0..598e7c4 100644
--- a/libweave/src/backoff_entry_unittest.cc
+++ b/libweave/src/backoff_entry_unittest.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "libweave/src/backoff_entry.h"
+#include "src/backoff_entry.h"
 
 #include <gtest/gtest.h>