lightnvm: if LUNs are already allocated fix return

While creating new device with NVM_DEV_CREATE if LUNs are already
allocated ioctl would return -ENOMEM which is wrong. This patch
propagates -EBUSY from nvm_reserve_luns which is correct response.

Fixes: ade69e243 ("lightnvm: merge gennvm with core")
Reviewed-by: Frans Klaver <[e-mail]>
Signed-off-by: Rakesh Pandit <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/lightnvm/core.c

···
 	}
 	mutex_unlock(&dev->mlock);
 
-	if (nvm_reserve_luns(dev, s->lun_begin, s->lun_end))
-		return -ENOMEM;
+	ret = nvm_reserve_luns(dev, s->lun_begin, s->lun_end);
+	if (ret)
+		return ret;
 
 	t = kmalloc(sizeof(struct nvm_target), GFP_KERNEL);
 	if (!t) {