When inserting devargs that is already in list,
existing one was reset and replaced completely by new one,
the entry info was lost during copy.
This patch backups entry info before copy.
Fixes: 64051bb1f144 ("devargs: unify scratch buffer storage")
Reported-by: Jim Harris <james.r.harris@intel.com>
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
e4b5b2ba9c