Revert "Avoid a potential race condition on mDisplays"

This reverts commit 5576a555a14edd8c76addce2cee37b9b9ced2c3f.

Change-Id: I5d5889fccd94acacfbfef29847e4b65ef2543c75
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 78d0307..81f1619 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -70,7 +70,7 @@
         friend class HWComposer;
         virtual void onVSyncReceived(
             HWComposer* composer, int32_t disp, nsecs_t timestamp) = 0;
-        virtual void onHotplugReceived(HWComposer* composer, int32_t disp, bool connected) = 0;
+        virtual void onHotplugReceived(int32_t disp, bool connected) = 0;
         virtual void onInvalidateReceived(HWComposer* composer) = 0;
     protected:
         virtual ~EventHandler() {}