All the MTD block write requests are failing with
following error messages
    mkfs.ext4  /dev/mtdblock0
    print_req_error: I/O error, dev mtdblock0, sector 0
    Buffer I/O error on dev mtdblock0, logical block 0,
    lost async page write
The control is going to default case after block write request
because of missing return.
Fixes: commit 2a842acab109 ("block: introduce new block status code type")
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
                for (; nsect > 0; nsect--, block++, buf += tr->blksize)
                        if (tr->writesect(dev, block, buf))
                                return BLK_STS_IOERR;
+               return BLK_STS_OK;
        default:
                return BLK_STS_IOERR;
        }