mtd: spi-nor-core: Don't check for zero length in spi_nor_write() / spi_nor_erase()

This check is already done in all callers: mtdcore's mtd_write() /
mtd_erase(), legacy spi_nor_write() / spi_flash_erase(). No reason to do
this here as well.

Signed-off-by: Marek BehĂșn <marek.behun@nic.cz>
1 file changed