Update doxygen tag
Update doxygen tag

- Changed : @returns -> @return

Change-Id: I44bdfdd47264b1c94a70f377272d5292d2a1e9d4
Signed-off-by: Seoyeon Kim <9d7945f986357c1681706fda3daa4250c146b2e7@samsung.com>

dalihub/dali-adaptor,dalihub/dali-adaptor,dalihub/dali-adaptor,dalihub/dali-adaptor,dalihub/dali-adaptor