ath9k: remove superfluous check on changing channel

ath9k: remove superfluous check on changing channel

When we try to change the channel in ath9k its because
either the configuration indicates we *have* changed
channels or HT configuration has changed. In both cases
we want to do a reset. Either way mac80211 will inform us
when we want to actually change the channel so trust those
calls.

Although in the patch it may seem as I am doing more code
changes I am not, all I am doing is removing the initial
branch conditional and shifting the code to the left.

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