ion: don't use id 0 for handle cookie

ion userspace clients think that the cookie is a pointer, so they
use NULL to check if the handle has been initialized.  Set the first
id number to 1.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion.c

@@ -424,7 +424,7 @@ static int ion_handle_add(struct ion_client *client, struct ion_handle *handle)
 		rc = idr_pre_get(&client->idr, GFP_KERNEL);
 		if (!rc)
 			return -ENOMEM;
-		rc = idr_get_new(&client->idr, handle, &id);
+		rc = idr_get_new_above(&client->idr, handle, 1, &id);
 		handle->id = id;
 	} while (rc == -EAGAIN);