snapshotctl: Initialize snapshot pointer when reverting snapshots

Test: snapshotctl revert-snapshots
Bug: 368487904
Change-Id: I9743bf412d4bfcf508aeb046ec329568da4e2be1
Signed-off-by: Akilesh Kailash <akailash@google.com>
diff --git a/fs_mgr/libsnapshot/snapshotctl.cpp b/fs_mgr/libsnapshot/snapshotctl.cpp
index 97a8cb2..46de991 100644
--- a/fs_mgr/libsnapshot/snapshotctl.cpp
+++ b/fs_mgr/libsnapshot/snapshotctl.cpp
@@ -105,7 +105,7 @@
     bool FinishSnapshotWrites();
     bool UnmapCowImagePath(std::string& name);
     bool DeleteSnapshots();
-    bool CleanupSnapshot() { return sm_->PrepareDeviceToBootWithoutSnapshot(); }
+    bool CleanupSnapshot();
     bool BeginUpdate();
     bool ApplyUpdate();
 
@@ -495,6 +495,11 @@
     return sm_->UnmapCowImage(name);
 }
 
+bool MapSnapshots::CleanupSnapshot() {
+    sm_ = SnapshotManager::New();
+    return sm_->PrepareDeviceToBootWithoutSnapshot();
+}
+
 bool MapSnapshots::DeleteSnapshots() {
     sm_ = SnapshotManager::New();
     lock_ = sm_->LockExclusive();