exposay: Fix logic inversion when ending keyboard grabs

I flipped a ! in cee82d6286
and the exposay keyboard grab became permanent.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>

desktop-shell/exposay.c

@@ -523,7 +523,7 @@ exposay_set_inactive(struct desktop_shell *shell)
 	if (seat->pointer_device_count)
 		weston_pointer_end_grab(seat->pointer);
 
-	if (!seat->keyboard_device_count) {
+	if (seat->keyboard_device_count) {
 		weston_keyboard_end_grab(seat->keyboard);
 		if (seat->keyboard->input_method_resource)
 			seat->keyboard->grab = &seat->keyboard->input_method_grab;