Fixed bug in 64-bit ecc_384_modp.

ChangeLog

 2013-02-27  Niels Möller  <nisse@lysator.liu.se>
 
+	* ecc-384.c (ecc_384_modp): Fixed typo which broke carry handling
+	in the 64-bit version.
+
 	* examples/ecc-benchmark.c (bench_add_jjj): Typo fix, benchmark
 	the right function.
 

ecc-384.c

@@ -114,7 +114,7 @@ ecc_384_modp (const struct ecc_curve *ecc, mp_limb_t *rp)
   /* Reduce from 9 to 6 limbs */
   tp[0] = 0;
   mpn_copyi (tp + 1, rp + 6, 2);
-  tp[3] = rp[8] -= mpn_sub_n (tp, tp, rp + 6, 3);
+  tp[3] = rp[8] - mpn_sub_n (tp, tp, rp + 6, 3);
   tp[4] = mpn_lshift (tp, tp, 4, 32);
 
   cy = mpn_add_n (rp, rp, rp + 6, 3);