HW reset calls pass the same variables or structs
which we can obtain easily from ah. Although this also applies
during channel changes as we will keep around the ath9k_channel
passed as an argument for now.

We now also now propagate the hw reset errors down.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>