Various changes suggested by cppcheck

- remove unused variables
- reduce the scope where it makes sense
- correct limits (did you know that strcat()'s last parameter does not
  include the \0 that is always added?)
- set some free()'d pointers to NULL

Source/Core/Core/Boot/Boot_BS2Emu.cpp

@@ -392,7 +392,6 @@ bool CBoot::EmulatedBS2_Wii()
 		Memory::Write_U32(firmwareVer ? firmwareVer : 0x00090204, 0x00003140);
 
 		// Load patches and run startup patches
-		std::string gameID = VolumeHandler::GetVolume()->GetUniqueID();
 		PatchEngine::LoadPatches();
 
 		// return