net: systemport: Fix CRC forwarding check for SYSTEMPORT Lite

net: systemport: Fix CRC forwarding check for SYSTEMPORT Lite

[ Upstream commit 9e3bff923913729d76d87f0015848ee7b8ff7083 ]

SYSTEMPORT Lite reversed the logic compared to SYSTEMPORT, the
GIB_FCS_STRIP bit is set when the Ethernet FCS is stripped, and that bit
is not set by default. Fix the logic such that we properly check whether
that bit is set or not and we don't forward an extra 4 bytes to the
network stack.

Fixes: 44a4524c54af ("net: systemport: Add support for SYSTEMPORT Lite")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>