Fix pessimizing move.

The std::move() here is unnecessary, and prohibits the compiler from
performing copy elision.

Change-Id: Ibdf515c4c0b0c07ff966c696e671a0526be1528e
diff --git a/keystore/operation.cpp b/keystore/operation.cpp
index 667f456..c77552e 100644
--- a/keystore/operation.cpp
+++ b/keystore/operation.cpp
@@ -30,7 +30,7 @@
                                        keymaster_key_characteristics_t* characteristics,
                                        bool pruneable) {
     sp<IBinder> token = new BBinder();
-    mMap[token] = std::move(Operation(handle, dev, characteristics, appToken));
+    mMap[token] = Operation(handle, dev, characteristics, appToken);
     if (pruneable) {
         mLru.push_back(token);
     }