git: Rework fread usages
git: Rework fread usages

This avoids decaying of C style arrays to pointers.

Change-Id: I72a178d3fa986aef7bbe2fa04913b0d7e1f82b16
Reviewed-by: Scott Parlane <85029adc3fa41ef14594a57826619713bfe95f25@alliedtelesis.co.nz>
Signed-off-by: Matt Bennett <e3d8681cec70d3da741935b3385821001b249adc@alliedtelesis.co.nz>

ATL-NZ/buildsyspp,alliedtelesis/buildsyspp