fcoe_init() calls fcoe_transport_attach(&fcoe_sw_transport), but when
fcoe_if_init() fails, &fcoe_sw_transport is not detached and leaves freed
&fcoe_sw_transport on fcoe_transports list. This causes panic when
reinserting module.

 BUG: unable to handle page fault for address: fffffbfff82e2213
 RIP: 0010:fcoe_transport_attach+0xe1/0x230 [libfcoe]
 Call Trace:
  <TASK>
  do_one_initcall+0xd0/0x4e0
  load_module+0x5eee/0x7210
  ...

Fixes: 78a58246 ("[SCSI] fcoe: convert fcoe.ko to become an fcoe transport provider driver")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Link: https://lore.kernel.org/r/20221115092442.133088-1-chenzhongjin@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>