Fix travis failure in f_impl.c
#include "field.h"
-#if (defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) && !I_HATE_UNROLLED_LOOPS) \
+#if (defined(__OPTIMIZE__) && !defined(__OPTIMIZE_SIZE__) && !defined(I_HATE_UNROLLED_LOOPS)) \
|| defined(C448_FORCE_UNROLL)
# define REPEAT8(_x) _x _x _x _x _x _x _x _x
# define FOR_LIMB(_i,_start,_end,_x) do { _i=_start; REPEAT8( if (_i<_end) { _x; } _i++;) } while (0)
