Fix HMAC memory issue

[farshadasl]

If the keyNative is NULL, then this line should not be called

OpenJCEPlus/src/main/native/ock/HMAC.c

Line 241 in 8d812f0

result = HMAC_init_internal(ockCtx, ockHMAC, keyNative, keySize);

It should be in the else block like this:

if (NULL == keyNative) {
...
} else {
  result = HMAC_init_internal(ockCtx, ockHMAC, keyNative, keySize);
  (*env)->ReleasePrimitiveArrayCritical(env, key, keyNative, 0);
}