fs: nfs: sysfs: use sysfs_emit() to instead of scnprintf()

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/sysfs.c

@@ -82,7 +82,7 @@ static ssize_t nfs_netns_identifier_show(struct kobject *kobj,
 	ssize_t ret;
 
 	rcu_read_lock();
-	ret = scnprintf(buf, PAGE_SIZE, "%s\n", rcu_dereference(c->identifier));
+	ret = sysfs_emit(buf, "%s\n", rcu_dereference(c->identifier));
 	rcu_read_unlock();
 	return ret;
 }