The nand_scan_ident/tail() returns an appropriate error value when
it fails.  Use it instead of the fixed error code -ENXIO.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NMarek Vasut <marek.vasut@gmail.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>