e1000e: Remove EN_MAC_ADDR_FILTER check from enable_mng_pass_thru check

Patch addresses issues when manageability passthrough is enabled, but the
MAC_ADDR_FILTER bit is not set in the MANC register.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>