stackctrl: Add "mp_" prefix.
diff --git a/unix/main.c b/unix/main.c
index 1bee639..176cbc6 100644
--- a/unix/main.c
+++ b/unix/main.c
@@ -214,7 +214,7 @@
 mp_obj_t mem_info(void) {
     printf("mem: total=%d, current=%d, peak=%d\n",
         m_get_total_bytes_allocated(), m_get_current_bytes_allocated(), m_get_peak_bytes_allocated());
-    printf("stack: %u\n", stack_usage());
+    printf("stack: %u\n", mp_stack_usage());
 #if MICROPY_ENABLE_GC
     gc_dump_info();
 #endif
@@ -265,7 +265,7 @@
 #endif
 
 int main(int argc, char **argv) {
-    stack_set_limit(32768);
+    mp_stack_set_limit(32768);
 
     pre_process_options(argc, argv);