mmc: davinci_mmc: Drop dangling variable

The sg_miter conversion left a dangling unused variable.
Drop it.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402142042.vg0lnLdb-lkp@intel.com/
Fixes: ed01d210

 ("mmc: davinci_mmc: Use sg_miter for PIO")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20240215-mmc-fix-davinci-v1-1-a593678ca7bf@linaro.org


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>