isolate_conflicts: don't look for eol that cannot be there.

isolate_conflicts: don't look for eol that cannot be there.

When looking for 'wiggles' we need to track whole lines
in the original file.  But when looking for an end-of-line
we shouldn't look at an merge-item that doesn't even
exist in the original file.

Reported-by: Chris Peterson <cpeterso@cpeterso.com>
Signed-off-by: NeilBrown <neilb@suse.de>