mtd: blkdevs: Fix mtd block write failure
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>