Revert "checkpoint: check checkpoint instead of assuming"

This reverts commit c0228607f340461e2e0448fabbba32756d1c2807.

Reason for revert: It seems necessary to force checkpoint.

Change-Id: I6889027538c0656b3689e008b03c1812317b22e6
diff --git a/crypto/fscrypt/MetadataCrypt.cpp b/crypto/fscrypt/MetadataCrypt.cpp
index e9b1967..853e81e 100755
--- a/crypto/fscrypt/MetadataCrypt.cpp
+++ b/crypto/fscrypt/MetadataCrypt.cpp
@@ -174,7 +174,7 @@
             unlink(newKeyPath.c_str());
     }
     bool needs_cp = cp_needsCheckpoint();
-    if (!retrieveOrGenerateKey(dir, temp, kEmptyAuthentication, gen, key, needs_cp)) return false;
+    if (!retrieveOrGenerateKey(dir, temp, kEmptyAuthentication, gen, key, true)) return false;
     if (needs_cp && pathExists(newKeyPath)) std::thread(commit_key, dir).detach();
     return true;
 }