ata: rb532_cf: Fix unused variable warning in rb532_pata_driver_probe

Fix the following warning (Building: rb532_defconfig mips):

drivers/ata/pata_rb532_cf.c: In function ‘rb532_pata_driver_remove’:
drivers/ata/pata_rb532_cf.c:161:24: warning: unused variable ‘info’ [-Wunused-variable]
  struct rb532_cf_info *info = ah->private_data;
                        ^~~~

Fixes: cd56f35e

 ("ata: rb532_cf: Convert to use GPIO descriptors")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>