Fix regression of #5694 (DISC0:)

Fix #5697
Maybe need @unknownbrackets to test more uppercase and lowercase 's behavior

ppsspp-v0.9.8-55-g66bf54e debug log (bad):
https://drive.google.com/file/d/0B3OaSdeV0L8kNFdEdWJjUE5Ecmc/edit?usp=sharing

Modify debug log (good):
https://drive.google.com/file/d/0B3OaSdeV0L8kdXZNWU5zQnpGUVk/edit?usp=sharing