[U-Boot] Stale references in the u-boot-samsung repo

[Albert ARIBAUD]

Hi Minkyu,

While fetching u-boot-samsung, I could see the following messages:

remote: error: refs/remotes/origin/GPL-Cleanup does not point to a
valid object!

remote: error: refs/remotes/origin/i.MX31 does not point to a valid
object!

remote: error: refs/remotes/origin/lwmon5 does not point to a valid
object!

remote: error: refs/remotes/origin/mkimage does not point to a valid
object!

It looks like these branches that were pushed on the remote, then later
the commit to which they point was cleaned up.

Can you fix this? Thanks in advance!

Amicalement,
-- 
Albert.