Although POSIX literally permits failing with [EINVAL] if IPC_CREAT and
IPC_EXCL were both passed, the semaphore set already exists and has fewer
semaphores than nsems, this does not allow an application to retry safely:
if the [EINVAL] is actually because of the semmsl limit, an infinite loop
would result.
PR: 206927
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.