mtd: Stop updating erase_info->state and calling mtd_erase_callback()

MTD users are no longer checking erase_info->state to determine if the
erase operation failed or succeeded. Moreover, mtd_erase_callback() is
now a NOP.

We can safely get rid of all mtd_erase_callback() calls and all
erase_info->state assignments. While at it, get rid of the
erase_info->state field, all MTD_ERASE_XXX definitions and the
mtd_erase_callback() function.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Bert Kenward <bkenward@solarflare.com>
---
Changes in v2:
- Address a few coding style issues (reported by Miquel)
- Remove comments that are no longer valid (reported by Miquel)

drivers/mtd/devices/docg3.c

@@ -1191,39 +1191,27 @@ static int doc_erase(struct mtd_info *mtd, struct erase_info *info)
 {
 	struct docg3 *docg3 = mtd->priv;
 	uint64_t len;
-	int block0, block1, page, ret, ofs = 0;
+	int block0, block1, page, ret = 0, ofs = 0;
 
 	doc_dbg("doc_erase(from=%lld, len=%lld\n", info->addr, info->len);
 
-	info->state = MTD_ERASE_PENDING;
 	calc_block_sector(info->addr + info->len, &block0, &block1, &page,
 			  &ofs, docg3->reliable);
-	ret = -EINVAL;
 	if (info->addr + info->len > mtd->size || page || ofs)
-		goto reset_err;
+		return -EINVAL;
 
-	ret = 0;
 	calc_block_sector(info->addr, &block0, &block1, &page, &ofs,
 			  docg3->reliable);
 	mutex_lock(&docg3->cascade->lock);
 	doc_set_device_id(docg3, docg3->device_id);
 	doc_set_reliable_mode(docg3);
 	for (len = info->len; !ret && len > 0; len -= mtd->erasesize) {
-		info->state = MTD_ERASING;
 		ret = doc_erase_block(docg3, block0, block1);
 		block0 += 2;
 		block1 += 2;
 	}
 	mutex_unlock(&docg3->cascade->lock);
 
-	if (ret)
-		goto reset_err;
-
-	info->state = MTD_ERASE_DONE;
-	return 0;
-
-reset_err:
-	info->state = MTD_ERASE_FAILED;
 	return ret;
 }