Prevent potential buffer overflow in sscanf

[moshekaplan]

Unbounded reads with sscanf can cause a buffer overflow when given an overly long string.

In this case, an adversary capable of modifying the .ini file would be able to trigger a buffer overflow in dolphin.

[delroth]

TBH an adversary with local access to the filesystem can do way worse things than exploit Dolphin... it provides no escalation path and thus is not really a security issue.

No reason to keep these kind of bugs though.

@dolphin-emu-bot rebuild

[Sonicadvance1]

Woo Android security!

[lioncash]

For what it's worth, we could probably use direct string handling + std::stoi and the family of similar funcs (or stringstream) and avoid the use of sscanf entirely.

Either way though, this looks fine.

[Sonicadvance1]

Yea. the string handling really should be improved.
Other priorities right now of course.