ath9k: remove !NULL check before kfree()

kfree(NULL) works so remove all those branches which check
for it before kfree()'ing on ath9k_hw_rfdetach().

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 file changed