nfsd: use DEFINE_PROC_SHOW_ATTRIBUTE to define nfsd_proc_ops

Use DEFINE_PROC_SHOW_ATTRIBUTE helper macro to simplify the code.
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/stats.c

@@ -32,7 +32,7 @@ struct svc_stat		nfsd_svcstats = {
 	.program	= &nfsd_program,
 };
 
-static int nfsd_proc_show(struct seq_file *seq, void *v)
+static int nfsd_show(struct seq_file *seq, void *v)
 {
 	int i;
 
@@ -72,17 +72,7 @@ static int nfsd_proc_show(struct seq_file *seq, void *v)
 	return 0;
 }
 
-static int nfsd_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, nfsd_proc_show, NULL);
-}
-
-static const struct proc_ops nfsd_proc_ops = {
-	.proc_open	= nfsd_proc_open,
-	.proc_read	= seq_read,
-	.proc_lseek	= seq_lseek,
-	.proc_release	= single_release,
-};
+DEFINE_PROC_SHOW_ATTRIBUTE(nfsd);
 
 int nfsd_percpu_counters_init(struct percpu_counter counters[], int num)
 {