Kernel commit e7bfb3fdbde3 ("mtd: Stop updating erase_info->state
and calling mtd_erase_callback()") removed erase_info->state
updates and calls of mtd_erase_callback().
Drop these erase callback invocations from AR2315 MTD driver as well.
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>