PR2490: Remove unused local variable bn ecp_nist.c

Reviewed-by: NDr. Stephen Henson <steve@openssl.org>

crypto/ec/ecp_nist.c

@@ -125,13 +125,11 @@ int ec_GFp_nist_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 	{
 	int ret = 0;
 	BN_CTX *new_ctx = NULL;
-	BIGNUM *tmp_bn;
 	
 	if (ctx == NULL)
 		if ((ctx = new_ctx = BN_CTX_new()) == NULL) return 0;
 
 	BN_CTX_start(ctx);
-	if ((tmp_bn = BN_CTX_get(ctx)) == NULL) goto err;
 
 	if (BN_ucmp(BN_get0_nist_prime_192(), p) == 0)
 		group->field_mod_func = BN_nist_mod_192;