devel/git-cinnabar: unbreak after 754ca6f4

Patching file git-core/csum-file.c using Plan A...
Hunk #1 failed at 86.
1 out of 1 hunks failed--saving rejects to helper/csum-file.patched.c.rej
done
gmake[2]: *** [helper/helper.mk:99: helper/csum-file.patched.c] Error 1