camera: do not use GNU old-style field designators

Summary: Not using a GNU extension improves portability

Test Plan: verified

Reviewers: randall.rushing, Roach, synergy

Reviewed By: synergy

Differential Revision: http://review.codefirex.com/D661

Change-Id: Ide483b7ff3a85473b0c30fb6aa0d8b58866199d1