Fix non-trivial warnings hidden by -isystem

These warnings were hidden by -isystem.

Bug: 31751828
Test: m -j checkbuild
Change-Id: Ibb1aa07a6827fcbd29fc15291fcd90280c0f608d
diff --git a/soundtrigger/SoundTrigger.cpp b/soundtrigger/SoundTrigger.cpp
index e959b83..289b7b1 100644
--- a/soundtrigger/SoundTrigger.cpp
+++ b/soundtrigger/SoundTrigger.cpp
@@ -124,9 +124,9 @@
 }
 
 // SoundTrigger
-SoundTrigger::SoundTrigger(sound_trigger_module_handle_t module,
+SoundTrigger::SoundTrigger(sound_trigger_module_handle_t /*module*/,
                                  const sp<SoundTriggerCallback>& callback)
-    : mModule(module), mCallback(callback)
+    : mCallback(callback)
 {
 }