parport_pc: make sure to release IO ports after probing for IT87XX

Commit f63fd7e2 ("parport_pc: detection
for SuperIO IT87XX POST") only released the IO port region on success,
not when the probe for the IT87XX chip failed.

That caused not only a reserved region to leak, but also caused an oops
when the driver module was unloaded and somebody tried to cat
/proc/ioports - because the string that was assigned to the IO port
region was a static string in the module virtual address area.

Reported-by: Lubos Lunak <l.lunak@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Petr Cvek <petr.cvek@tul.cz>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>