block: unexport various bio mapping helpers

They are unused and potential new users really should use the
blk_rq_map* versions.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

block/bio.c

@@ -1101,7 +1101,6 @@ int bio_uncopy_user(struct bio *bio)
 	bio_put(bio);
 	return ret;
 }
-EXPORT_SYMBOL(bio_uncopy_user);
 
 /**
  *	bio_copy_user_iov	-	copy user data to bio
@@ -1396,7 +1395,6 @@ void bio_unmap_user(struct bio *bio)
 	__bio_unmap_user(bio);
 	bio_put(bio);
 }
-EXPORT_SYMBOL(bio_unmap_user);
 
 static void bio_map_kern_endio(struct bio *bio)
 {
@@ -1542,7 +1540,6 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
 	bio_put(bio);
 	return ERR_PTR(-ENOMEM);
 }
-EXPORT_SYMBOL(bio_copy_kern);
 
 /*
  * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions