igb: Fix Rx packet type encoding

igb: Fix Rx packet type encoding

igb's advanced descriptor uses a packet type encoding different from
one used in e1000e's extended descriptor. Fix the logic to encode
Rx packet type accordingly.

Fixes: 3a977deebe ("Intrdocue igb device emulation")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech>
Signed-off-by: Jason Wang <jasowang@redhat.com>
(cherry picked from commit ed447c60b341f1714b3c800d7f9c68898e873f78)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>