https://bugs.dolphin-emu.org/issues/11888
This also includes another change: DolphinQt will now exit with an
error if you use --batch without specifying a game using any method
(unlike in the past where --batch would be ignored if you didn't
specify a game using --exec, even if you had used --nand-title).
The main reason why I did this was because coding the alternative
(ignoring --batch) would be annoying with render to main involved.