When fix the Coverity scan report, a use-after-free bug is introduced.

After using the English mode in ibus-libpinyin, some random file is created in the home directory after re-login.


Reproducible: Always

Steps to Reproduce:
1. Open gnome-text-editor, switch to "Intelligent Pinyin" input method
2. Enter "vEnglish", and press the space key
3. After re-login, some random file is created in the Home directory
Actual Results:
Some random file is created in the home directory.

Expected Results:
The sqlite file is stored in the ~/.cache/ibus/libpinyin directory.