[FS#241] ath9k strange behaviour since wireless-testing 2016-10-08

[LEDE Bugs]

The following task has a new comment added:

FS#241 - ath9k strange behaviour since wireless-testing 2016-10-08
User who did this - xinglp (xinglp)

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I have same issue with ar9331, revert this commit fix my problem.
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=241#comment743