USB: serial: keyspan: fix memleak on probe errors

USB: serial: keyspan: fix memleak on probe errors

I got memory leak as follows when doing fault injection test:

unreferenced object 0xffff888258228440 (size 64):
  comm "kworker/7:2", pid 2005, jiffies 4294989509 (age 824.540s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8167939c>] slab_post_alloc_hook+0x9c/0x490
    [<ffffffff8167f627>] kmem_cache_alloc_trace+0x1f7/0x470
    [<ffffffffa02ac0e4>] keyspan_port_probe+0xa4/0x5d0 [keyspan]
    [<ffffffffa0294c07>] usb_serial_device_probe+0x97/0x1d0 [usbserial]
    [<ffffffff82b50ca7>] really_probe+0x167/0x460
    [<ffffffff82b51099>] __driver_probe_device+0xf9/0x180
    [<ffffffff82b51173>] driver_probe_device+0x53/0x130
    [<ffffffff82b516f5>] __device_attach_driver+0x105/0x130
    [<ffffffff82b4cfe9>] bus_for_each_drv+0x129/0x190
    [<ffffffff82b50a69>] __device_attach+0x1c9/0x270
    [<ffffffff82b518d0>] device_initial_probe+0x20/0x30
    [<ffffffff82b4f062>] bus_probe_device+0x142/0x160
    [<ffffffff82b4a4e9>] device_add+0x829/0x1300
    [<ffffffffa0295fda>] usb_serial_probe.cold+0xc9b/0x14ac [usbserial]
    [<ffffffffa02266aa>] usb_probe_interface+0x1aa/0x3c0 [usbcore]
    [<ffffffff82b50ca7>] really_probe+0x167/0x460

If keyspan_port_probe() fails to allocate memory for an out_buffer[i] or
in_buffer[i], the previously allocated memory for out_buffer or
in_buffer needs to be freed on the error handling path, otherwise a
memory leak will result.

Fixes: bad41a5bf177 ("USB: keyspan: fix port DMA-buffer allocations")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Link: https://lore.kernel.org/r/20211015085543.1203011-1-wanghai38@huawei.com
Cc: stable@vger.kernel.org      # 3.12
Signed-off-by: Johan Hovold <johan@kernel.org>