t/t7503-pre-commit-hook.sh: Add GIT_PREFIX tests
t/t7503-pre-commit-hook.sh: Add GIT_PREFIX tests

Ensure that the pre-commit hook has access to GIT_PREFIX.

Signed-off-by: David Aguilar <9de348c050f7cd1ca590883733c4e531ce610bf4@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git