test/recv-multishot.c: check for error specifically when submitting
test/recv-multishot.c: check for error specifically when submitting

Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@kernel.dk>

axboe/liburing,axboe/liburing,axboe/liburing