Fix unused lambda capture warnings from libweave.

Fixes following warnings:
libweave/src/privet/privet_handler.cc:384:16: error: lambda capture 'this' is not used [-Werror,-Wunused-lambda-capture]
       auto pred = [this](const UpdateRequestParameters& params) {
libweave/src/privet/privet_handler.cc:396:16: error: lambda capture 'this' is not used [-Werror,-Wunused-lambda-capture]
libweave-0.0.1-r240:   auto pred = [this](const UpdateRequestParameters& params) {

BUG=chromium:714984
TEST=Warnings are gone

Change-Id: I3ac2fbdc16b3ba7880e17c2091a40ca7e35379fe
Reviewed-on: https://weave-review.googlesource.com/9930
Reviewed-by: Eric Caruso <ejcaruso@google.com>
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
diff --git a/src/privet/privet_handler.cc b/src/privet/privet_handler.cc
index 25b2e4c..086d54c 100644
--- a/src/privet/privet_handler.cc
+++ b/src/privet/privet_handler.cc
@@ -381,7 +381,7 @@
 
 void PrivetHandler::OnCommandDefsChanged() {
   ++command_defs_fingerprint_;
-  auto pred = [this](const UpdateRequestParameters& params) {
+  auto pred = [](const UpdateRequestParameters& params) {
     return params.command_defs_fingerprint < 0;
   };
   auto last =
@@ -393,7 +393,7 @@
 
 void PrivetHandler::OnStateChanged() {
   ++state_fingerprint_;
-  auto pred = [this](const UpdateRequestParameters& params) {
+  auto pred = [](const UpdateRequestParameters& params) {
     return params.state_fingerprint < 0;
   };
   auto last =