bcachefs: Delete dio read alignment check

We'll typically fomat devices with the physical blocksize supported, but
the logical blocksize will be smaller.

There's no real need to be checking the blocksize at the filesystem
level, anyways - the block layer has to check this anyways.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/fs-io-direct.c

@@ -77,9 +77,6 @@ static int bch2_direct_IO_read(struct kiocb *req, struct iov_iter *iter)
 
 	bch2_inode_opts_get(&opts, c, &inode->ei_inode);
 
-	if ((offset|iter->count) & (block_bytes(c) - 1))
-		return -EINVAL;
-
 	ret = min_t(loff_t, iter->count,
 		    max_t(loff_t, 0, i_size_read(&inode->v) - offset));