driver: soc: xilinx: fix memory leak in xlnx_add_cb_for_notify_event()

The kfree() should be called when memory fails to be allocated for
cb_data in xlnx_add_cb_for_notify_event(), otherwise there will be
a memory leak, so add kfree() to fix it.

Fixes: 05e5ba40 ("driver: soc: xilinx: Add support of multiple callbacks for same event in event management driver")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20221129010146.1026685-1-cuigaosheng1@huawei.comSigned-off-by: Michal Simek <michal.simek@amd.com>

drivers/soc/xilinx/xlnx_event_manager.c

@@ -116,8 +116,10 @@ static int xlnx_add_cb_for_notify_event(const u32 node_id, const u32 event, cons
 		INIT_LIST_HEAD(&eve_data->cb_list_head);
 
 		cb_data = kmalloc(sizeof(*cb_data), GFP_KERNEL);
-		if (!cb_data)
+		if (!cb_data) {
+			kfree(eve_data);
 			return -ENOMEM;
+		}
 		cb_data->eve_cb = cb_fun;
 		cb_data->agent_data = data;