Miscalculations on secp384 curve

Hi,

Attached is an example elliptic curve multiplication that will produce a wrong result in nettle.

It's a multiplication of these coordinates 23000000000000000000000000000000000000000000000000110011C2DD0000000000000000000 46BE3FEF75FCA4BD52CE28EC3F1483A05EE154965B05282F9029E14277409908C0EBAAD2CA5449FFA61FEC78473816BC with this scalar 23000000000000C1DD3FF800E83E2CACA1010A21

The example code will do the calculation with both openssl and nettle and will produce different results (I have verified the result with nss, which produces the same result as openssl).

Compile with gcc nettle-nistp384-miscalc.c -lhogweed -lgmp -lcrypto