libxfs-apply: support filterdiff >= 0.4.2 only

libxfs-apply: support filterdiff >= 0.4.2 only

We currently require filterdiff v0.3.4 as a minimum for handling git
based patches. This was the first version to handle git diff
metadata well enough to do patch reformatting. It was, however, very
buggy and required several workarounds to get it to do what we
needed.

However, these bugs have been fixed and on a machine with v0.4.2,
the workarounds result in libxfs-apply breaking and creating corrupt
patches. Rather than try to carry around workarounds for a broken
filterdiff version and one that just works, just increase the
minimum required version to 0.4.2 and remove all the workarounds for
the bugs in 0.3.4.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>