cxgb4 : Fix DCB priority groups being returned in wrong order

Peer priority groups were being reversed, but this was missed in the previous
fix sent out for this issue.

v2 : Previous patch was doing extra unnecessary work, result is the same.
Please ignore previous patch

Fixes :	ee7bc3cd ('cxgb4 : dcb open-lldp interop fixes')

Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>