Remove stale dependency to libhwc2on1adaptor.so.

This commit removes stale dependency to libhwc2on1adaptor.  Since commit
831d48ed, mAdapter has become an unused private member.  In addition,
this unused unique_ptr leads to an unnecessary symbol reference to the
destructor of HWC2on1Adaptor.  This commit removes them completely.

Bug: 38302528
Test: Sailfish builds and boots.
Change-Id: I479f12ddbae91282a13464159f00513aa7cb3208
diff --git a/services/surfaceflinger/Android.mk b/services/surfaceflinger/Android.mk
index 0071851..c1cb70e 100644
--- a/services/surfaceflinger/Android.mk
+++ b/services/surfaceflinger/Android.mk
@@ -80,7 +80,6 @@
     libdl \
     libfmq \
     libhardware \
-    libhwc2on1adapter \
     libhidlbase \
     libhidltransport \
     libhwbinder \
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 0f49e61..42be935 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -47,7 +47,6 @@
 #include <log/log.h>
 
 #include "HWComposer.h"
-#include "hwc2on1adapter/HWC2On1Adapter.h"
 #include "HWC2.h"
 #include "ComposerHal.h"
 
@@ -61,8 +60,7 @@
 // ---------------------------------------------------------------------------
 
 HWComposer::HWComposer(bool useVrComposer)
-    : mAdapter(),
-      mHwcDevice(),
+    : mHwcDevice(),
       mDisplayData(2),
       mFreeDisplaySlots(),
       mHwcDisplaySlots(),
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 631af14..3eb968d 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -58,7 +58,6 @@
 class Fence;
 class FloatRect;
 class GraphicBuffer;
-class HWC2On1Adapter;
 class NativeHandle;
 class Region;
 class String8;
@@ -205,7 +204,6 @@
         HWC2::Vsync vsyncEnabled;
     };
 
-    std::unique_ptr<HWC2On1Adapter> mAdapter;
     std::unique_ptr<HWC2::Device>   mHwcDevice;
     std::vector<DisplayData>        mDisplayData;
     std::set<size_t>                mFreeDisplaySlots;