greybus: endo: fix ida memory leak

Fix yet another ida memory leak due to failure to call the destructor.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/endo.c

@@ -547,4 +547,5 @@ int __init gb_endo_init(void)
 
 void gb_endo_exit(void)
 {
+	ida_destroy(&greybus_endo_id_map);
 }