sdio: sdio_io.c Fix sparse warnings

Unfold nested macros it creates not readable code and
sparse warnings
sdio_io.c:190:9: warning: symbol '_min1' shadows an earlier one

Signed-off-by: Tomas Winkler <[e-mail]>
Signed-off-by: Pierre Ossman <[e-mail]>

drivers/mmc/core/sdio_io.c

···
  */
 static inline unsigned int sdio_max_byte_size(struct sdio_func *func)
 {
-	return min(min(min(
-		func->card->host->max_seg_size,
-		func->card->host->max_blk_size),
-		func->max_blksize),
-		512u); /* maximum size for byte mode */
+	unsigned mval =	min(func->card->host->max_seg_size,
+			    func->card->host->max_blk_size);
+	mval = min(mval, func->max_blksize);
+	return min(mval, 512u); /* maximum size for byte mode */
 }
 
 /**