dasd: unexport dasd_set_target_state

dasd_set_target_state is only used inside of dasd_mod.ko, so don't
export it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20210701142221.3408680-2-sth@linux.ibm.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/s390/block/dasd.c

@@ -621,7 +621,6 @@ void dasd_set_target_state(struct dasd_device *device, int target)
 	mutex_unlock(&device->state_mutex);
 	dasd_put_device(device);
 }
-EXPORT_SYMBOL(dasd_set_target_state);
 
 /*
  * Enable devices with device numbers in [from..to].