f2fs: fix f2fs_show_options to show nodiscard mount option

Fix f2fs_show_options to show nodiscard mount option.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/super.c

@@ -1313,6 +1313,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 		seq_puts(seq, ",disable_roll_forward");
 	if (test_opt(sbi, DISCARD))
 		seq_puts(seq, ",discard");
+	else
+		seq_puts(seq, ",nodiscard");
 	if (test_opt(sbi, NOHEAP))
 		seq_puts(seq, ",no_heap");
 	else