memcheck: fixed for PX4 build

libraries/memcheck/memcheck.cpp

@@ -41,7 +41,7 @@ void memcheck_update_stackptr(void)
  */
 void memcheck_init(void)
 {
-#if CONFIG_HAL_BOARD != HAL_BOARD_AVR_SITL
+#if CONFIG_HAL_BOARD == HAL_BOARD_APM1 || CONFIG_HAL_BOARD == HAL_BOARD_APM2
     uint32_t *p;
     free(malloc(1)); // ensure heap is initialised
     stack_low = current_stackptr();
@@ -58,13 +58,13 @@ void memcheck_init(void)
  */
 unsigned memcheck_available_memory(void)
 {
-#if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
-    return 0x1000;
-#else
+#if CONFIG_HAL_BOARD == HAL_BOARD_APM1 || CONFIG_HAL_BOARD == HAL_BOARD_APM2
     memcheck_update_stackptr();
     while (*stack_low != SENTINEL && stack_low > (const uint32_t *)__brkval) {
         stack_low--;
     }
     return (uintptr_t)(stack_low) - __brkval;
+#else
+    return 0x1000;
 #endif
 }