qdev: Fix device_add DRIVER,help to print to monitor

Help on device properties gets printed to stdout instead of the
monitor.  If you have the monitor anywhere else, no help for you.
Broken when commit e1043d6 "qdev: use object_property_help()"
accidentally switched from qemu_printf() to printf().  Switch right
back.

Fixes: e1043d6
Cc: Marc-André Lureau <[email protected]>
Cc: [email protected]
Signed-off-by: Markus Armbruster <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Li Qiang <[email protected]>
Reviewed-by: Dr. David Alan Gilbert <[email protected]>

Author: Markus Armbruster

qdev-monitor.c

@@ -300,7 +300,7 @@ int qdev_device_help(QemuOpts *opts)
     }
     g_ptr_array_sort(array, (GCompareFunc)qemu_pstrcmp0);
     for (i = 0; i < array->len; i++) {
-        printf("%s\n", (char *)array->pdata[i]);
+        qemu_printf("%s\n", (char *)array->pdata[i]);
     }
     g_ptr_array_set_free_func(array, g_free);
     g_ptr_array_free(array, true);