ecl: defcallback: fix calling-convention (#93)
ecl: defcallback: fix calling-convention (#93)

This is for bytecmp and the C compiler compatibility. :cdecl doesn't
work on Android, but :default works just fine. For C compiled code there
is no difference.
cffi/cffi,attila-lendvai/cffi,dkochmanski/cffi,3b/cffi,3b/cffi,mcna/cffi,stassats/cffi,stassats/cffi,3b/cffi,attila-lendvai/cffi,dkochmanski/cffi,mcna/cffi,cffi/cffi,stassats/cffi,cffi/cffi,dkochmanski/cffi