Kill comments saying to remove asserts once bug930 is solved.

It's okay to leave the asserts in: the code doesn't appear in profiles.

src/common/memarea.c

@@ -53,7 +53,7 @@ realign_pointer(void *ptr)
 {
   uintptr_t x = (uintptr_t)ptr;
   x = (x+MEMAREA_ALIGN_MASK) & ~MEMAREA_ALIGN_MASK;
-  tor_assert(((void*)x) >= ptr); // XXXX021 remove this once bug 930 is solved
+  tor_assert(((void*)x) >= ptr);
   return (void*)x;
 }
 
@@ -230,9 +230,10 @@ memarea_alloc(memarea_t *area, size_t sz)
   }
   result = chunk->next_mem;
   chunk->next_mem = chunk->next_mem + sz;
-  // XXXX021 remove these once bug 930 is solved.
+
   tor_assert(chunk->next_mem >= chunk->u.mem);
   tor_assert(chunk->next_mem <= chunk->u.mem+chunk->mem_size);
+
   chunk->next_mem = realign_pointer(chunk->next_mem);
   return result;
 }