ath9k: Unlock sc->mutex on error path

An error path in ath9k_add_interface() did not unlock the sc->mutex and
could leave the driver in quite unresponsive state.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
1 file changed