ion:synchronize debugfs callback and ion_client_destroy

There are race condition B/T ion_client_destroy and debugfs callbacks.
Let's use a mutex to synchronize them.

Signed-off-by: Neil Zhang <neilzhang1123@hotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed