Correct comment

For file-based encryption, /data/adb is always required to encrypt
https://android.googlesource.com/platform/system/extras/+/refs/tags/android-7.0.0_r36/ext4_utils/ext4_crypt_init_extensions.cpp
https://android.googlesource.com/platform/system/core/+/68258e8444e0daa967b007edf659e8bb7b38c59f%5E%21/

native/jni/core/bootstages.cpp

@@ -289,7 +289,7 @@ void post_fs_data(int client) {
         } else {
             // If the folder is not automatically created by Android,
             // do NOT proceed further. Manual creation of the folder
-            // will cause bootloops on FBE devices.
+            // will have no encryption flag, which will cause bootloops on FBE devices.
             LOGE(SECURE_DIR " is not present, abort\n");
             goto early_abort;
         }