parport: fix interruptible_sleep_on race

The interruptible_sleep_on function is can still lead to the
deadlock mentioned in the comment above the caller, and we want
to remove it soon, so replace it now with the race-free
wait_event_interruptible.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>