Check correct err variable on wifi keystore HAL

Test: rebuild source code and flash it to phone (Pixel 3a), which works.
Change-Id: I152470dd9f6f5a8a7793eefd0cfb2f8d8d483205
diff --git a/keystore/keystore_main.cpp b/keystore/keystore_main.cpp
index 45c3feb..9e358c9 100644
--- a/keystore/keystore_main.cpp
+++ b/keystore/keystore_main.cpp
@@ -167,7 +167,7 @@
     configureRpcThreadpool(1, false /* callerWillJoin */);
     android::sp<IKeystore> wifiKeystoreHalService = new Keystore();
     android::status_t err = wifiKeystoreHalService->registerAsService();
-    CHECK(ret == android::OK) << "Cannot register wifi keystore HAL service: " << err;
+    CHECK(err == android::OK) << "Cannot register wifi keystore HAL service: " << err;
 
     /*
      * This thread is just going to process Binder transactions.