ath6kl: Fix system freeze under heavy data load

ath6kl: Fix system freeze under heavy data load

Patch "ath6kl: Fix buffer alignment for scatter-gather write" does
memmove for a length (scat_req->scat_list[i].len) which is not the
actual length of data that is suppossed to be moved. The right
lengh is packet->act_len + HTC_HDR_LENGTH. Using wrong length
for data move during buffer alignment causes system freeze after
the following WARN_ON and sometimes target assert.

WARNING: at drivers/net/wireless/ath/ath6kl/main.c:771 ath6k_credit_distribute+0x196/0x1a0
 [<ffffffffa051cf5f>] ath6kl_htc_rxmsg_pending_handler+0x83f/0xe00 [ath6kl]
 [<ffffffff8104a743>] ? __wake_up+0x53/0x70
 [<ffffffffa0518b18>] ath6kldev_intr_bh_handler+0x188/0x650 [ath6kl]
 [<ffffffffa052d316>] ath6kl_sdio_irq_handler+0x36/0x80 [ath6kl]
 [<ffffffff81492b3c>] sdio_irq_thread+0xfc/0x360
 [<ffffffff81051c52>] ? default_wake_function+0x12/0x20
 [<ffffffff81492a40>] ? sdio_claim_irq+0x220/0x220
 [<ffffffff81080c36>] kthread+0x96/0xa0
 [<ffffffff815b9fb4>] kernel_thread_helper+0x4/0x10
 [<ffffffff81080ba0>] ? kthread_worker_fn+0x190/0x190
 [<ffffffff815b9fb0>] ? gs_change+0x13/0x13

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>