liburing: improve output for test/io_uring_setup.c
liburing: improve output for test/io_uring_setup.c

For the IORING_SETUP_SQPOLL|IORING_SETUP_SQ_AFF test case, add_pipe is
not set, and the output is like:
"...flags: IORING_SETUP_SQPOLLIORING_SETUP_SQ_AFF...".

Set add_pipe for IORING_SETUP_SQPOLL flag so that the output is like:
"...flags: IORING_SETUP_SQPOLL|IORING_SETUP_SQ_AFF...".

Acked-by: Jeff Moyer <cd6badf7869d996b866599075536a600ed1910b5@redhat.com>
Signed-off-by: Shenghui Wang <bb485778c59c959c620dcf404550d8d7642fd953@foxmail.com>
Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@kernel.dk>

axboe/liburing,axboe/liburing,axboe/liburing