bcachefs: drop duplicate fiemap sync flag

FIEMAP_FLAG_SYNC handling was deliberately moved into core code in
commit 45dd052 ("fs: handle FIEMAP_FLAG_SYNC in fiemap_prep"),
released in kernel v5.8. Update bcachefs accordingly.

Signed-off-by: Brian Foster <bfoster@redhat.com>

Author: Brian Foster

fs/bcachefs/fs.c

@@ -1330,7 +1330,7 @@ static int bch2_fiemap(struct inode *vinode, struct fiemap_extent_info *info,
 	bool have_extent = false;
 	int ret = 0;
 
-	ret = fiemap_prep(&ei->v, info, start, &len, FIEMAP_FLAG_SYNC);
+	ret = fiemap_prep(&ei->v, info, start, &len, 0);
 	if (ret)
 		return ret;