Minor fix on UserSystemPackageInstaller.checkWhitelistedSystemPackages().

Test: adb shell cmd user report-system-user-package-whitelist-problems --mode 1 -v

Bug: 154112291

Change-Id: I6be1462293b9b6f739dabcef55d008764ab54265

services/core/java/com/android/server/pm/UserSystemPackageInstaller.java

@@ -306,7 +306,7 @@ class UserSystemPackageInstaller {
                 + numberErrors + " errors:");
 
         boolean doWtf = !isImplicitWhitelistMode(mode);
-        for (int i = 0; i < numberWarnings; i++) {
+        for (int i = 0; i < numberErrors; i++) {
             final String msg = errors.get(i);
             if (doWtf) {
                 Slog.wtf(TAG, msg);