btrfs/064: add a comment to the test case header

It appears that the goal of this case was to test balance and
replace concurrency. But these two operations aren't meant to run
concurrently and the replace failing errors are captured in the
seqres.full output. Which are expected errors. To avoid further
confusion, this patch adds comments. The reason to keep this
test case is at the Link.

Link: https://patchwork.kernel.org/patch/11806307/
Reported-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
1 file changed