btrfs-progs: corrupt block, add missing break to option I

Using -I would imply -d.

Resolves-Coverity-CID: 1258792
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>

btrfs-corrupt-block.c

@@ -1096,6 +1096,7 @@ int main(int ac, char **av)
 				break;
 			case 'I':
 				corrupt_item = 1;
+				break;
 			case 'd':
 				delete = 1;
 				break;