Core: Remove unused variable
Core: Remove unused variable

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