dex which
caused the system to panic. Ideally ath9k need to loop only for the
indexes that were part of the retry series and so simply use hw->max_rates
as the loop counter.

Pasted the stack trace of the panic issue for reference.

[  754.093192] BUG: unable to handle kernel paging request at ffff88046a9025b0
[  754.093256] IP: [<ffffffffa02eac49>] ath_tx_status+0x209/0x2f0 [ath9k]
[  754.094888] Call Trace:
[  754.094903]  <IRQ>
[  754.094928]  [<ffffffffa051f883>] ieee80211_tx_status+0x203/0x9e0 [mac80211]
[  754.094975]  [<ffffffffa053e305>] ? __ieee80211_wake_queue+0x125/0x140 [mac80211]
[  754.095017]  [<ffffffffa02e66c9>] ath_tx_complete_buf+0x1b9/0x370 [ath9k]
[  754.095054]  [<ffffffffa02e6fcf>] ath_tx_complete_aggr+0x51f/0xb50 [ath9k]
[  754.095098]  [<ffffffffa05382a3>] ? ieee80211_prepare_and_rx_handle+0x173/0xab0 [mac80211]
[  754.095148]  [<ffffffff81350e62>] ? _raw_spin_unlock_irqrestore+0x32/0x40
[  754.095186]  [<ffffffffa02e9735>] ath_tx_tasklet+0x365/0x4b0 [ath9k]
[  754.095224]  [<ffffffff8107a2a2>] ? clockevents_program_event+0x62/0xa0
[  754.095261]  [<ffffffffa02e2628>] ath9k_tasklet+0x168/0x1c0 [ath9k]
[  754.095298]  [<ffffffff8105599b>] tasklet_action+0x6b/0xe0
[  754.095331]  [<ffffffff81056278>] __do_softirq+0x98/0x120
[  754.095361]  [<ffffffff8100cd5c>] call_softirq+0x1c/0x30
[  754.095393]  [<ffffffff8100efb5>] do_softirq+0x65/0xa0
[  754.095423]  [<ffffffff810563fd>] irq_exit+0x8d/0x90
[  754.095453]  [<ffffffff8100ebc1>] do_IRQ+0x61/0xe0
[  754.095482]  [<ffffffff81351413>] ret_from_intr+0x0/0x15
[  754.095513]  <EOI>
[  754.095531]  [<ffffffff81014375>] ? native_sched_clock+0x15/0x70
[  754.096475]  [<ffffffffa02bcfa6>] ? acpi_idle_enter_bm+0x24d/0x285 [processor]
[  754.096475]  [<ffffffffa02bcf9f>] ? acpi_idle_enter_bm+0x246/0x285 [processor]
[  754.096475]  [<ffffffff8127fab2>] cpuidle_idle_call+0x82/0x100
[  754.096475]  [<ffffffff8100a236>] cpu_idle+0xa6/0xf0
[  754.096475]  [<ffffffff81339bc1>] rest_init+0x91/0xa0
[  754.096475]  [<ffffffff814efccd>] start_kernel+0x3fd/0x408
[  754.096475]  [<ffffffff814ef347>] x86_64_start_reservations+0x132/0x136
[  754.096475]  [<ffffffff814ef451>] x86_64_start_kernel+0x106/0x115
[  754.096475] RIP  [<ffffffffa02eac49>] ath_tx_status+0x209/0x2f0 [ath9k]

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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