bnx2x: mark LRO as a fixed disabled feature if disable_tpa is set

If disable_tpa is set, remove NETIF_F_LRO from hw_features, so ethtool sees
it as "off [fixed]".

Note that setting the NETIF_F_LRO bit in dev->features in the 'else'
branch is not needed, because the bit was already set by
bnx2x_init_dev().

Then the check for disable_tpa in in bnx2x_fix_features() becomes unnecessary.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>