btrfs-progs: corrupt-block: Correctly handle -r when passing -I
The documentation for the -I option (corrupt an item) states:
An item to corrupt (must also specify the field to corrupt and a root+key for the item)
The code on the other hand doesn't check whether -r is in fact passed,
and even if it is it's not handled at all. This means presently -I
is possible to corrupt items only in the root tree. Fix this by
correctly checking -r is passed and fail otherwise and passing the
correct root to corrupt_btrfs_item.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>