After DEV_RX_OFFLOAD_JUMBO_FRAME flag removed, drivers give jumbo frame
decisions based on MTU value checks, but some of the checks were wrong
by mistake, causing device initialization to fail, fixing them.
Fixes: b563c1421282 ("ethdev: remove jumbo offload flag")
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Tested-by: Yu Jiang <yux.jiang@intel.com>