NFS: 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/namespace.c

@@ -354,7 +354,7 @@ static int param_get_nfs_timeout(char *buffer, const struct kernel_param *kp)
 			num = (num + (HZ - 1)) / HZ;
 	} else
 		num = -1;
-	return scnprintf(buffer, PAGE_SIZE, "%li\n", num);
+	return sysfs_emit(buffer, "%li\n", num);
 }
 
 static const struct kernel_param_ops param_ops_nfs_timeout = {