f2fs: set CP_TRIMMED_FLAG correctly

Don't set CP_TRIMMED_FLAG for non-zoned block device or discard
unsupported device, it can avoid to trigger unneeded checkpoint for
that kind of device.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/super.c

@@ -587,7 +587,7 @@ static void f2fs_put_super(struct super_block *sb)
 	/* be sure to wait for any on-going discard commands */
 	f2fs_wait_discard_bios(sbi);
 
-	if (!sbi->discard_blks) {
+	if (f2fs_discard_en(sbi) && !sbi->discard_blks) {
 		struct cp_control cpc = {
 			.reason = CP_UMOUNT | CP_TRIMMED,
 		};