tests: Add null checks in torture_pki_ed25519.c

Signed-off-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

tests/unittests/torture_pki_ed25519.c

@@ -263,6 +263,7 @@ static void torture_pki_ed25519_write_privkey(void **state)
             NULL,
             &origkey);
     assert_true(rc == 0);
+    assert_non_null(origkey);
 
     unlink(LIBSSH_ED25519_TESTKEY);
 
@@ -279,6 +280,7 @@ static void torture_pki_ed25519_write_privkey(void **state)
             NULL,
             &privkey);
     assert_true(rc == 0);
+    assert_non_null(privkey);
 
     rc = ssh_key_cmp(origkey, privkey, SSH_KEY_CMP_PRIVATE);
     assert_true(rc == 0);
@@ -307,6 +309,7 @@ static void torture_pki_ed25519_write_privkey(void **state)
             NULL,
             &privkey);
     assert_true(rc == 0);
+    assert_non_null(privkey);
 
     rc = ssh_key_cmp(origkey, privkey, SSH_KEY_CMP_PRIVATE);
     assert_true(rc == 0);
@@ -322,6 +325,7 @@ static void torture_pki_ed25519_write_privkey(void **state)
                                      NULL,
                                      &origkey);
     assert_true(rc == 0);
+    assert_non_null(origkey);
 
     unlink(LIBSSH_ED25519_TESTKEY_PASSPHRASE);
     rc = ssh_pki_export_privkey_file(origkey,
@@ -345,6 +349,7 @@ static void torture_pki_ed25519_write_privkey(void **state)
                                      NULL,
                                      &privkey);
     assert_true(rc == 0);
+    assert_non_null(privkey);
 
     rc = ssh_key_cmp(origkey, privkey, SSH_KEY_CMP_PRIVATE);
     assert_true(rc == 0);