igb_uio: use non-threaded ISR
igb_uio: use non-threaded ISR

This eliminates the overhead of a task switch when an interrupt arrives.

Signed-off-by: David Su <a22a38ea9771a15b83707b667ae0a7d004276670@intel.com>
Acked-by: Ferruh Yigit <ba8734c3c506d2e3557bd4ac8fdaccd25bdb9aa7@intel.com>

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