misc: mic: vop: vop_main: Remove set but unused variable 'ret'

misc: mic: vop: vop_main: Remove set but unused variable 'ret'

Hasn't been checked since its conception 2 years ago.

Squashes W=1 warning:

 drivers/misc/mic/vop/vop_main.c: In function ‘_vop_scan_devices’:
 drivers/misc/mic/vop/vop_main.c:617:6: warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]
 617 | int ret;
 | ^~~

Cc: Sudeep Dutt <sudeep.dutt@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200626130525.389469-8-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>