Ignore DE retrieveKey failure for non-user-0

retrieveKey can fail in load_all_de_keys if a user
is partially removed, i.e. cases where
fscrypt_destroy_user_key() got interrupted. So just
ignore the failure, else could reboot into recovery.

Test: pm create-user foo
      pm remove-user 10
      adb reboot && check device not enter recovery

Signed-off-by: liulvping <liulvping@xiaomi.com>
Change-Id: Iba9d53a0833524d00e65d0427ab03002c5d8d509
diff --git a/FsCrypt.cpp b/FsCrypt.cpp
index 85ffefd..481f680 100644
--- a/FsCrypt.cpp
+++ b/FsCrypt.cpp
@@ -414,7 +414,11 @@
         userid_t user_id = std::stoi(entry->d_name);
         auto key_path = de_dir + "/" + entry->d_name;
         KeyBuffer de_key;
-        if (!retrieveKey(key_path, kEmptyAuthentication, &de_key)) return false;
+        if (!retrieveKey(key_path, kEmptyAuthentication, &de_key)) {
+            // This is probably a partially removed user, so ignore
+            if (user_id != 0) continue;
+            return false;
+        }
         EncryptionPolicy de_policy;
         if (!install_storage_key(DATA_MNT_POINT, options, de_key, &de_policy)) return false;
         auto ret = s_de_policies.insert({user_id, de_policy});