libertas: don't set URB_ZERO_PACKET on IN USB transfer

libertas: don't set URB_ZERO_PACKET on IN USB transfer

The USB core gets rightfully upset:

  usb 1-1: BOGUS urb flags, 240 --> 200
  WARNING: CPU: 0 PID: 60 at drivers/usb/core/urb.c:503 usb_submit_urb+0x2f8/0x3ed
  Modules linked in:
  CPU: 0 PID: 60 Comm: kworker/0:3 Not tainted 4.19.0-rc6-00319-g5206d00a45c7 #39
  Hardware name: OLPC XO/XO, BIOS OLPC Ver 1.00.01 06/11/2014
  Workqueue: events request_firmware_work_func
  EIP: usb_submit_urb+0x2f8/0x3ed
  Code: 75 06 8b 8f 80 00 00 00 8d 47 78 89 4d e4 89 55 e8 e8 35 1c f6 ff 8b 55 e8 56 52 8b 4d e4 51 50 68 e3 ce c7 c0 e8 ed 18 c6 ff <0f> 0b 83 c4 14 80 7d ef 01 74 0a 80 7d ef 03 0f 85 b8 00 00 00 8b
  EAX: 00000025 EBX: ce7d4980 ECX: 00000000 EDX: 00000001
  ESI: 00000200 EDI: ce7d8800 EBP: ce7f5ea8 ESP: ce7f5e70
  DS: 007b ES: 007b FS: 0000 GS: 00e0 SS: 0068 EFLAGS: 00210292
  CR0: 80050033 CR2: 00000000 CR3: 00e80000 CR4: 00000090
  Call Trace:
   ? if_usb_fw_timeo+0x64/0x64
   __if_usb_submit_rx_urb+0x85/0xe6
   ? if_usb_fw_timeo+0x64/0x64
   if_usb_submit_rx_urb_fwload+0xd/0xf
   if_usb_prog_firmware+0xc0/0x3db
   ? _request_firmware+0x54/0x47b
   ? _request_firmware+0x89/0x47b
   ? if_usb_probe+0x412/0x412
   lbs_fw_loaded+0x55/0xa6
   ? debug_smp_processor_id+0x12/0x14
   helper_firmware_cb+0x3c/0x3f
   request_firmware_work_func+0x37/0x6f
   process_one_work+0x164/0x25a
   worker_thread+0x1c4/0x284
   kthread+0xec/0xf1
   ? cancel_delayed_work_sync+0xf/0xf
   ? kthread_create_on_node+0x1a/0x1a
   ret_from_fork+0x2e/0x38
  ---[ end trace 3ef1e3b2dd53852f ]---

Cc: stable@vger.kernel.org
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>