net: fix amd-xgbe flow-control issue

If we enable or disable xgbe flow-control by ethtool ,
it does't work.Because the parameter is not properly
assigned,so we need to adjust the assignment order
of the parameters.

Fixes: c1ce2f77 ("amd-xgbe: Fix flow control setting logic")
Signed-off-by: tangpengpeng <tangpengpeng@higon.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>