xen-netback: remove unecessary condition check before debugfs_remove_recursive

debugfs_remove_recursive has taken IS_ERR_OR_NULL into account. So just
remove the condition check before debugfs_remove_recursive.

Signed-off-by: zhong jiang <[email protected]>
Reviewed-by: Paul Durrant <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 3621e05..80aae3a 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1660,8 +1660,7 @@ module_init(netback_init);
 static void __exit netback_fini(void)
 {
 #ifdef CONFIG_DEBUG_FS
-	if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
-		debugfs_remove_recursive(xen_netback_dbg_root);
+	debugfs_remove_recursive(xen_netback_dbg_root);
 #endif /* CONFIG_DEBUG_FS */
 	xenvif_xenbus_fini();
 }