xen: xenbus: Use helper function IS_ERR_OR_NULL()

Use IS_ERR_OR_NULL() to detect an error pointer or a null pointer
open-coding to simplify the code.

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230817014736.3094289-1-lizetao1@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c
index 3f3836cb72799bc1d6b63f586246deda11e6030d..fcb335bb7b1878c690532d5e854f7703bd6af25b 100644 (file)
--- a/drivers/xen/xenbus/xenbus_probe_frontend.c
+++ b/drivers/xen/xenbus/xenbus_probe_frontend.c
@@ -429,7 +429,7 @@ static void xenbus_check_frontend(char *class, char *dev)
                printk(KERN_DEBUG "XENBUS: frontend %s %s\n",
                                frontend, xenbus_strstate(fe_state));
                backend = xenbus_read(XBT_NIL, frontend, "backend", NULL);
-               if (!backend || IS_ERR(backend))
+               if (IS_ERR_OR_NULL(backend))
                        goto out;
                err = xenbus_scanf(XBT_NIL, backend, "state", "%i", &be_state);
                if (err == 1)