vold: use RAII wake locks

Prevents wake lock leaks, e.g. b/133175847

Bug: 133175847
Test: boot blueline
Change-Id: I62fd1c6c3abbfd35aebe11343abd717a7cf4eef7
diff --git a/MoveStorage.cpp b/MoveStorage.cpp
index 79a47ae..9b806ec 100644
--- a/MoveStorage.cpp
+++ b/MoveStorage.cpp
@@ -258,15 +258,13 @@
 
 void MoveStorage(const std::shared_ptr<VolumeBase>& from, const std::shared_ptr<VolumeBase>& to,
                  const android::sp<android::os::IVoldTaskListener>& listener) {
-    acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLock);
+    android::power::WakeLock wl{kWakeLock};
 
     android::os::PersistableBundle extras;
     status_t res = moveStorageInternal(from, to, listener);
     if (listener) {
         listener->onFinished(res, extras);
     }
-
-    release_wake_lock(kWakeLock);
 }
 
 }  // namespace vold