test/msg-recvall: fix test
test/msg-recvall: fix test

We should expect just half of the requested amount for a DGRAM socket.

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

axboe/liburing,axboe/liburing,axboe/liburing