staging: mt29f_spinand: check for the return value of spinand_read_status

The spinan_read_status can fail, check for the return value and
fail if the spinand_read_status fails.

Cc: Kamlakant Patel <kamlakant.patel@broadcom.com>
Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>