ath9k_hw: Fix magnitude/phase coeff correction

ath9k_hw: Fix magnitude/phase coeff correction

commit e9c10469cf3c71bc1c6b0f01319161e277d6ac9b upstream.

Do the magnitude/phase coeff correction only if the outlier
is detected. Updating wrong magnitude/phase coeff factor
impacts not only tx gain setting but also leads to poor
performance in congested networks. In the clear environment
the impact is very minimal because the outlier happens
very rarely according to the past experiment. It occured
less than once every 1000 calibrations.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>