crypto: dh - fix memory leak

In case memory resources for *base* were allocated, release them
before return.

Addresses-Coverity-ID: 1471702 ("Resource leak")
Fixes: e3fe0ae1 ("crypto: dh - add public key verification test")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/dh.c

@@ -174,7 +174,7 @@ static int dh_compute_value(struct kpp_request *req)
 		}
 		ret = dh_is_pubkey_valid(ctx, base);
 		if (ret)
-			goto err_free_val;
+			goto err_free_base;
 	} else {
 		base = ctx->g;
 	}