Coverity 1507372: explicit null dereference

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/18822)

test/evp_extra_test2.c

@@ -346,9 +346,8 @@ static int test_dh_tofrom_data_select(void)
           && TEST_int_gt(EVP_PKEY_generate(gctx, &key), 0)
           && TEST_true(do_pkey_tofrom_data_select(key, "DHX"));
 # ifndef OPENSSL_NO_DEPRECATED_3_0
-    dhkey = EVP_PKEY_get0_DH(key);
-    ret = ret && TEST_ptr(dhkey);
-    ret = ret && TEST_ptr(privkey = DH_get0_priv_key(dhkey))
+    ret = ret && TEST_ptr(dhkey = EVP_PKEY_get0_DH(key))
+              && TEST_ptr(privkey = DH_get0_priv_key(dhkey))
               && TEST_int_le(BN_num_bits(privkey), 225);
 # endif
     EVP_PKEY_free(key);