libinstaller: Avoid using <linux/ext2_fs.h>

libinstaller: Avoid using <linux/ext2_fs.h>

Don't use <linux/ext2_fs.h> if we can avoid it.

The ioctl constants have been globalized and moved to <linux/fs.h>.
Use a private copy of ext2_fs.h from e2fsprogs with the ioctl
constants removed for the data structures.

Do at least attempt backward compatibility for old kernel headers, but
no real hope of proper operation there...

[ Doing this as a cherry-pick to unblock this branch ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Resolved Conflicts:

	libinstaller/linuxioctl.h