sfc: fix potential memleak in __ef100_hard_start_xmit()

The __ef100_hard_start_xmit() returns NETDEV_TX_OK without freeing skb
in error handling case, add dev_kfree_skb_any() to fix it.

Fixes: 51b35a45 ("sfc: skeleton EF100 PF driver")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Martin Habets <habetsm.xilinx@gmail.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/1668671409-10909-1-git-send-email-zhangchangzhong@huawei.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>