nand: fix nand torture to use changed mtd api

The mtd subsystem deprecated and renamed the direct use of the mtd_info
struct's functionpointers. Instead the corresponding mtd_xxx function
should be used.

See also:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3c3c10bba1e4ccb75b41442e45c1a072f6cded19

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
index 9b61087..5bba66a 100644
--- a/drivers/mtd/nand/nand_util.c
+++ b/drivers/mtd/nand/nand_util.c
@@ -847,7 +847,7 @@
 	}
 
 	for (i = 0; i < patt_count; i++) {
-		err = mtd->erase(mtd, &instr);
+		err = mtd_erase(mtd, &instr);
 		if (err) {
 			printf("%s: erase() failed for block at 0x%llx: %d\n",
 				mtd->name, instr.addr, err);
@@ -855,7 +855,7 @@
 		}
 
 		/* Make sure the block contains only 0xff bytes */
-		err = mtd->read(mtd, offset, mtd->erasesize, &retlen, buf);
+		err = mtd_read(mtd, offset, mtd->erasesize, &retlen, buf);
 		if ((err && err != -EUCLEAN) || retlen != mtd->erasesize) {
 			printf("%s: read() failed for block at 0x%llx: %d\n",
 				mtd->name, instr.addr, err);
@@ -872,14 +872,14 @@
 
 		/* Write a pattern and check it */
 		memset(buf, patterns[i], mtd->erasesize);
-		err = mtd->write(mtd, offset, mtd->erasesize, &retlen, buf);
+		err = mtd_write(mtd, offset, mtd->erasesize, &retlen, buf);
 		if (err || retlen != mtd->erasesize) {
 			printf("%s: write() failed for block at 0x%llx: %d\n",
 				mtd->name, instr.addr, err);
 			goto out;
 		}
 
-		err = mtd->read(mtd, offset, mtd->erasesize, &retlen, buf);
+		err = mtd_read(mtd, offset, mtd->erasesize, &retlen, buf);
 		if ((err && err != -EUCLEAN) || retlen != mtd->erasesize) {
 			printf("%s: read() failed for block at 0x%llx: %d\n",
 				mtd->name, instr.addr, err);