exfat: Fix discard support

Discard support was always unconditionally disabled. Now it is disabled
only in the case when blk_queue_discard() returns false.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

fs/exfat/super.c

@@ -531,10 +531,11 @@ static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
 	if (opts->discard) {
 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
 
-		if (!blk_queue_discard(q))
+		if (!blk_queue_discard(q)) {
 			exfat_msg(sb, KERN_WARNING,
 				"mounting with \"discard\" option, but the device does not support discard");
-		opts->discard = 0;
+			opts->discard = 0;
+		}
 	}
 
 	sb->s_flags |= SB_NODIRATIME;