net: fec: remove the xdp_return_frame when lack of tx BDs

In the implementation, the sent_frame count does not increment when
transmit errors occur. Therefore, bq_xmit_all() will take care of
returning the XDP frames.

Fixes: 26312c68 ("net: fec: correct the counting of XDP sent frames")
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>