audio VTS: Fix call to IDevice::close in V6 tests

The result of RPC calls of HAL methods must be checked.
Added a check of result of calling IDevice::close added
for V6.

Bug: 114451103
Test: atest VtsHalAudioV6_0TargetTest
Change-Id: Ib6276382f15f122b43f314cf64cac2c3242bb76c
diff --git a/audio/core/all-versions/vts/functional/DeviceManager.h b/audio/core/all-versions/vts/functional/DeviceManager.h
index d849f85..cb6584d 100644
--- a/audio/core/all-versions/vts/functional/DeviceManager.h
+++ b/audio/core/all-versions/vts/functional/DeviceManager.h
@@ -113,7 +113,11 @@
 #elif MAJOR_VERSION >= 6
         {
             sp<IDevice> device = getExisting(std::make_tuple(factoryName, name));
-            if (device != nullptr) device->close();
+            if (device != nullptr) {
+                auto ret = device->close();
+                ALOGE_IF(!ret.isOk(), "Device %s::%s close failed: %s", factoryName.c_str(),
+                         name.c_str(), ret.description().c_str());
+            }
         }
         return InterfaceManager::reset(std::make_tuple(factoryName, name), false);
 #endif