media: ov5693: fix returnvar.cocci warnings

drivers/media/i2c/ov5693.c:953:5-8: Unneeded variable: "ret". Return "0" on line 985

 Remove unneeded variable used to store return value.

Generated by: scripts/coccinelle/misc/returnvar.cocci

[Sakari Ailus: Improved subject]

CC: Daniel Scally <djrscally@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>