This fixes a performance issue when pc & gpt partmap iterators
didn't abort iteration even after our hook found what it was
looking for (often causing expensive probes of non-existant drives).
Some callers relied on previous buggy behaviour, since they would
rise an error when their own hooks caused early abortion of its
iteration.
* kern/device.c (grub_device_open): Improve error message.
* disk/lvm.c (grub_lvm_open): Likewise.
* disk/raid.c (grub_raid_open): Likewise.
* partmap/pc.c (pc_partition_map_iterate): Abort parent iteration
when hook requests it, independently of grub_errno.
(pc_partition_map_probe): Do not fail when find_func() caused
early abortion of pc_partition_map_iterate().
* partmap/gpt.c (gpt_partition_map_iterate): Abort parent iteration
when hook requests it, independently of grub_errno.
(gpt_partition_map_probe): Do not fail when find_func() caused
early abortion of gpt_partition_map_iterate().
* kern/partition.c (grub_partition_iterate): Abort parent iteration
when hook requests it, independently of grub_errno. Do not fail when
part_map_iterate_hook() caused early abortion of p->iterate().
* util/biosdisk.c (grub_util_biosdisk_get_grub_dev): Do not fail
when grub_partition_iterate() returned with non-zero.
8516d2a8e1