mmc: davinci_mmc: Drop dangling variable

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

Reported-by: kernel test robot <[e-mail]>
Closes: https://lore.kernel.org/oe-kbuild-all/[e-mail]/
Fixes: ed01d210fd91 ("mmc: davinci_mmc: Use sg_miter for PIO")
Signed-off-by: Linus Walleij <[e-mail]>
Acked-by: Bartosz Golaszewski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/mmc/host/davinci_mmc.c

···
 					unsigned int n)
 {
 	struct sg_mapping_iter *sgm = &host->sg_miter;
-	size_t sglen;
 	u8 *p;
 	unsigned int i;
 
···
 		return;
 	}
 	p = sgm->addr;
-	sglen = sgm->length;
 
 	/* NOTE:  we never transfer more than rw_threshold bytes
 	 * to/from the fifo here; there's no I/O overlap.