minor tweaks, safety note

Author: robamu

examples/track_usage.rs

@@ -38,13 +38,12 @@ fn main() -> ! {
 
     drop(alloc_vecs);
 
-    defmt::warn!(
+    defmt::info!(
         "{} of {} heap memory are allocated after drop",
         HEAP_SIZE - HEAP.free(),
         HEAP_SIZE
     );
 
-    // Panic is expected here.
     semihosting::process::exit(0);
 }
 

src/tlsf.rs

@@ -115,6 +115,8 @@ impl Heap {
         if !inner_mut.initialized {
             return 0;
         }
+        // Safety: We pass the memory block we previously initialized the heap with
+        // to the `iter_blocks` method.
         unsafe {
             inner_mut
                 .tlsf