btrfs-progs: repair: remove recowed entry from the to-recow list

If we attempt to repair a filesystem with metadata blocks that need
recowing, we'll get into an infinite loop repeatedly recowing the
first entry in the list, without ever removing it from the list.
Oops.  Fixed.

Signed-off-by: Alexandre Oliva <oliva@gnu.org>
Signed-off-by: David Sterba <dsterba@suse.cz>

cmds-check.c

@@ -7034,6 +7034,7 @@ int cmd_check(int argc, char **argv)
 
 		eb = list_first_entry(&root->fs_info->recow_ebs,
 				      struct extent_buffer, recow);
+		list_del_init(&eb->recow);
 		ret = recow_extent_buffer(root, eb);
 		if (ret)
 			break;