SDL: Fix crashing on GB game exit
SDL: Fix crashing on GB game exit

iracigt/mgba,iracigt/mgba,iracigt/mgba,Anty-Lemon/mgba,Anty-Lemon/mgba,sergiobenrocha2/mgba,fr500/mgba,Touched/mgba,fr500/mgba,MerryMage/mgba,sergiobenrocha2/mgba,MerryMage/mgba,Iniquitatis/mgba,fr500/mgba,fr500/mgba,Iniquitatis/mgba,libretro/mgba,jeremyherbert/mgba,Anty-Lemon/mgba,libretro/mgba,jeremyherbert/mgba,Anty-Lemon/mgba,jeremyherbert/mgba,sergiobenrocha2/mgba,mgba-emu/mgba,mgba-emu/mgba,mgba-emu/mgba,Touched/mgba,MerryMage/mgba,jeremyherbert/mgba,sergiobenrocha2/mgba,libretro/mgba,Touched/mgba,sergiobenrocha2/mgba,Iniquitatis/mgba,Iniquitatis/mgba,libretro/mgba,iracigt/mgba,mgba-emu/mgba,libretro/mgba