Fix malloc_hooks for hooks_write_malloc_leak_info.

Change-Id: I99f9ee0221bc7bbb5e7dd173ae5a6007f0fa871d
diff --git a/libc/malloc_hooks/malloc_hooks.cpp b/libc/malloc_hooks/malloc_hooks.cpp
index 662520c..f7bdd56 100644
--- a/libc/malloc_hooks/malloc_hooks.cpp
+++ b/libc/malloc_hooks/malloc_hooks.cpp
@@ -69,6 +69,7 @@
     void (*callback)(uintptr_t base, size_t size, void* arg), void* arg);
 void hooks_malloc_disable();
 void hooks_malloc_enable();
+bool hooks_write_malloc_leak_info(FILE*);
 
 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
 void* hooks_pvalloc(size_t bytes);
@@ -216,6 +217,10 @@
   return 0;
 }
 
+bool hooks_write_malloc_leak_info(FILE*) {
+  return true;
+}
+
 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
 void* hooks_pvalloc(size_t bytes) {
   size_t pagesize = getpagesize();