Turn builtin_exec_path into a function.
Turn builtin_exec_path into a function.

builtin_exec_path returns the hard-coded installation path, which is used
as the ultimate fallback to look for git commands. Making it into a function
enables us in a follow-up patch to return a computed value instead of just
a constant string.

Signed-off-by: Johannes Sixt <5cc107486946fdcf16e86d7c808fa50f4312125f@telecom.at>

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