Rip out non-endomorphism code

src/group_impl.h

@@ -646,7 +646,6 @@ static SECP256K1_INLINE void secp256k1_ge_storage_cmov(secp256k1_ge_storage *r,
     secp256k1_fe_storage_cmov(&r->y, &a->y, flag);
 }
 
-#ifdef USE_ENDOMORPHISM
 static void secp256k1_ge_mul_lambda(secp256k1_ge *r, const secp256k1_ge *a) {
     static const secp256k1_fe beta = SECP256K1_FE_CONST(
         0x7ae96a2bul, 0x657c0710ul, 0x6e64479eul, 0xac3434e9ul,
@@ -655,7 +654,6 @@ static void secp256k1_ge_mul_lambda(secp256k1_ge *r, const secp256k1_ge *a) {
     *r = *a;
     secp256k1_fe_mul(&r->x, &r->x, &beta);
 }
-#endif
 
 static int secp256k1_gej_has_quad_y_var(const secp256k1_gej *a) {
     secp256k1_fe yz;