dm-flakey: Fix memory corruption in optional corrupt_bio_byte feature

Fix memory corruption due to incorrect parameter being passed to bio_init

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org	# v6.5+
Fixes: 1d9a9438 ("dm flakey: clone pages on write bio before corrupting them")