heap trace standalone: Fix initialization of the unused linked list, update tests

- Call TAILQ_INSERT_TAIL in linked_list_setup to add unused records from the tail of the list
- Fix test "heap trace leak check" to expect that after a free, the record is zeroed instead of checking that
  the whole list of records is moved by one index in the array.
- Use esp_rom_printf() under lock instead of printf() since it does not rely on interrupts.

components/heap/test_apps/main/test_heap_main.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -8,7 +8,7 @@
 #include "unity_test_runner.h"
 #include "esp_heap_caps.h"
 
-#define TEST_MEMORY_LEAK_THRESHOLD_DEFAULT -100
+#define TEST_MEMORY_LEAK_THRESHOLD_DEFAULT -300
 static int leak_threshold = TEST_MEMORY_LEAK_THRESHOLD_DEFAULT;
 void set_leak_threshold(int threshold)
 {

components/heap/test_apps/main/test_heap_trace.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
@@ -66,9 +66,9 @@ TEST_CASE("heap trace leak check", "[heap-trace]")
     heap_trace_get(0, &trace_b);
     TEST_ASSERT_EQUAL_PTR(b, trace_b.address);
 
-    /* buffer deletes trace_a when freed,
-       so trace_b at head of buffer */
-    TEST_ASSERT_EQUAL_PTR(recs[0].address, trace_b.address);
+    /* trace_a freed and placed back to unused list,
+       so recs[0].address is 0*/
+    TEST_ASSERT_EQUAL_PTR(recs[0].address, 0x00);
 
     heap_trace_stop();
 }