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- Remove comments that are no longer valid (reported by Miquel)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/lart.c

@@ -414,10 +414,7 @@ static int flash_erase (struct mtd_info *mtd,struct erase_info *instr)
    while (len)
 	 {
 		if (!erase_block (addr))
-		  {
-			 instr->state = MTD_ERASE_FAILED;
 			 return (-EIO);
-		  }
 
 		addr += mtd->eraseregions[i].erasesize;
 		len -= mtd->eraseregions[i].erasesize;
@@ -425,9 +422,6 @@ static int flash_erase (struct mtd_info *mtd,struct erase_info *instr)
 		if (addr == mtd->eraseregions[i].offset + (mtd->eraseregions[i].erasesize * mtd->eraseregions[i].numblocks)) i++;
 	 }
 
-   instr->state = MTD_ERASE_DONE;
-   mtd_erase_callback(instr);
-
    return (0);
 }