io_uring_submit: note specifics on return value for SQPOLL

Added the following behavior of io_uring_submit to the man page. When
used with SQ_POLL and in the success case, the return value may not
indicate the actual amount of successfully submitted submission queue
entries, as mentioned in issue 88

Signed-off-by: Constantin Pestka constantin.pestka@web.de
1 file changed