surfaceflinger: Remove unnecessary std::move

Moving a temporary object prevents copy elision, and could reduce
performance.

This fixes -Wpessimizing-move compiler warning.

Test: presubmit
Bug: 154270751
Change-Id: I745e7dbcbde53eed95111e78d1251bea43b3869f
diff --git a/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp b/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
index 12ab2c2..be95913 100644
--- a/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
+++ b/services/surfaceflinger/DisplayHardware/HidlComposerHal.cpp
@@ -209,7 +209,7 @@
     if (!buffer || buffer->initCheck() != ::android::OK) {
         return nullptr;
     }
-    return std::move(buffer);
+    return buffer;
 }
 
 } // anonymous namespace