elm_photocam: add NULL check
elm_photocam: add NULL check

@fix

Reviewers: woohyun, jaehwan, eunue

Differential Revision: https://phab.enlightenment.org/D3429

tasn/elementary,rvandegrift/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary,tasn/elementary