[PATCH] rt2x00: Fix panic on rmmod with rfkill enabled

When ieee80211_hw.config indicates that the radio
is enabled and is configuring options that require
the link tuner to be restarted the link tuner will
cause a kernel panic when rfkill has indicated the
radio was in fact disabled.

Signed-off-by: Modestas Vainius <modestas@vainius.eu>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>