Rename iterate to malloc_iterate internally.

I have no idea why I used the iterate name internally which is
completely unlike every other function name. Change this to match
everyone else so that it's now malloc_iterate everywhere.

This is probably the last chance to change this before mainline
modules begin, so make everything consistent.

Test: Compiles, unit tests passes.
Change-Id: I56d293377fa0fe1a3dc3dd85d6432f877cc2003c
diff --git a/libc/bionic/malloc_limit.cpp b/libc/bionic/malloc_limit.cpp
index 6a67cae..d8c0ebe 100644
--- a/libc/bionic/malloc_limit.cpp
+++ b/libc/bionic/malloc_limit.cpp
@@ -350,9 +350,9 @@
 static int LimitIterate(uintptr_t base, size_t size, void (*callback)(uintptr_t, size_t, void*), void* arg) {
   auto dispatch_table = GetDefaultDispatchTable();
   if (__predict_false(dispatch_table != nullptr)) {
-    return dispatch_table->iterate(base, size, callback, arg);
+    return dispatch_table->malloc_iterate(base, size, callback, arg);
   }
-  return Malloc(iterate)(base, size, callback, arg);
+  return Malloc(malloc_iterate)(base, size, callback, arg);
 }
 
 static void LimitMallocDisable() {