memory: Clean up how mtree_info() prints

mtree_info() takes an fprintf()-like callback and a FILE * to pass to
it, and so do its helper functions.  Passing around callback and
argument is rather tiresome.

Its only caller hmp_info_mtree() passes monitor_printf() cast to
fprintf_function and the current monitor cast to FILE *.

The type-punning is technically undefined behaviour, but works in
practice.  Clean up: drop the callback, and call qemu_printf()
instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-9-armbru@redhat.com>

include/exec/memory.h

@@ -1720,8 +1720,7 @@ void memory_global_dirty_log_start(void);
  */
 void memory_global_dirty_log_stop(void);
 
-void mtree_info(fprintf_function mon_printf, void *f, bool flatview,
-                bool dispatch_tree, bool owner);
+void mtree_info(bool flatview, bool dispatch_tree, bool owner);
 
 /**
  * memory_region_dispatch_read: perform a read directly to the specified