ext2fs inode size fix never MFC'd

[Josh Carroll]

I just noticed that the changes to the ext2 code to support inode
sizes other than 128 was never MFC'd:

http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/gnu/fs/ext2fs/ext2_linux_ialloc.c?r1=1.25.8.1;sortby=date#diff

I submitted a patch to this PR:

http://www.freebsd.org/cgi/query-pr.cgi?pr=124621&cat=

Which was partially adopted (or at least the same idea was used) and
committed to HEAD back in January, but the MFC after 2 weeks to
RELENG_7 never happened, unfortunately.

I was hoping this would make it into 7.1, and I seem to have noticed
this too late for 7.2-RELEASE but can someone get this merged into
RELENG_7?

Regards,
Josh