wifi: ath9k: cleanup ath9k_hw_get_nf_hist_mid()

In 'ath9k_hw_get_nf_hist_mid()', prefer 'memcpy()' and 'sort()'
over an ad-hoc things. Briefly tested as a separate module.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20250109080703.106692-1-dmantipov@yandex.ru


Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>