Trim trailing spaces in FAT label and support mtools-like labels
* fs/fat.c (grub_fat_iterate_dir): New function based
on grub_fat_find_dir
(grub_fat_find_dir): use grub_fat_iterate_dir
(grub_fat_label): likewise
Leak fixes
* kern/disk.c (grub_disk_cache_store): Invalidate previous cache
in case of collision
* disk/scsi.c (grub_scsi_open): free scsi in case of error