* disk/ieee1275/nand.c (grub_nand_iterate): Return

	* disk/ieee1275/nand.c (grub_nand_iterate): Return
	grub_devalias_iterate() result instead of unconditional 0.
	* disk/ieee1275/ofdisk.c (grub_ofdisk_iterate): Likewise.
	Also, capture hook return value, either directly or via
	grub_children_iterate(), and propagate to caller.
	* include/grub/ieee1275/ieee1275.h (grub_devalias_iterate,
	grub_children_iterate): Return value is now 'int' instead of
	'grub_err_t'.
	* kern/ieee1275/openfw.c (grub_children_iterate): Fix to behave
	like a proper iterator, stopping when hooks return non-zero.
	(grub_devalias_iterate): Likewise.