io_uring: remove redundant initialization of variable ret

mainline inclusion
from mainline-v5.12-rc1
commit 4a245479
category: bugfix
bugzilla: 186136, https://gitee.com/openeuler/kernel/issues/I4RM1D


CVE: NA

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The variable ret is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Fixes: b63534c4 ("io_uring: re-issue block requests that failed because of resources")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
conflict:
        fs/io_uring.c
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>