vulkan: Remove unused variable

Change-Id: Ie7ae9a699e1de225364edd65767ddd95d9cc1c1e
diff --git a/system/vulkan/goldfish_vulkan.cpp b/system/vulkan/goldfish_vulkan.cpp
index 44071ec..720300d 100644
--- a/system/vulkan/goldfish_vulkan.cpp
+++ b/system/vulkan/goldfish_vulkan.cpp
@@ -354,9 +354,11 @@
     } \
     goldfish_vk::ResourceTracker::get()->setupFeatures(rcEnc->featureInfo_const()); \
     goldfish_vk::ResourceTracker::ThreadingCallbacks threadingCallbacks = { \
-        [] { auto hostCon = HostConnection::get(); \
-            ExtendedRCEncoderContext *rcEnc = hostCon->rcEncoder(); \
-            return hostCon; }, \
+        [] { \
+          auto hostCon = HostConnection::get(); \
+          hostCon->rcEncoder(); \
+          return hostCon; \
+        }, \
         [](HostConnection* hostCon) { return hostCon->vkEncoder(); }, \
     }; \
     goldfish_vk::ResourceTracker::get()->setThreadingCallbacks(threadingCallbacks); \