i40e: fix interrupt disabling when stopping
i40e: fix interrupt disabling when stopping

When stop device, should disable interrupt of FDIR but not
enable it. This patch corrected it.

Signed-off-by: Jingjing Wu <64d28b617c3b4840f5ded1bfa611cba7fadfe5c7@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk