Fix missing initializations on some error paths

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index a7ed262..06e0816 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -699,16 +699,16 @@
     int ret;
     size_t len = 0;
     mbedtls_asn1_named_data *names = NULL;
-    mbedtls_x509_name parsed, *parsed_cur, *parsed_prv;
-    unsigned char buf[1024], out[1024], *c;
+    mbedtls_x509_name parsed;
+    memset(&parsed, 0, sizeof(parsed));
+    mbedtls_x509_name *parsed_cur = NULL;
+    mbedtls_x509_name *parsed_prv = NULL;
+    unsigned char buf[1024] = {0};
+    unsigned char out[1024] = {0};
+    unsigned char *c = buf + sizeof(buf);
 
     USE_PSA_INIT();
 
-    memset(&parsed, 0, sizeof(parsed));
-    memset(out, 0, sizeof(out));
-    memset(buf, 0, sizeof(buf));
-    c = buf + sizeof(buf);
-
     ret = mbedtls_x509_string_to_names(&names, name);
     TEST_EQUAL(ret, result);