Fix printing of invalid struct sembuf.sem_flg
Fix printing of invalid struct sembuf.sem_flg

* ipc_sem.c (print_sembuf): Explicitly cast struct sembuf.sem_flg
to unsigned short to avoid potential sign-extension bug when printing
invalid struct sembuf.sem_flg.

Saruta/strace,cuviper/strace,Saruta/strace,cuviper/strace,Saruta/strace,cuviper/strace,cuviper/strace,cuviper/strace,Saruta/strace,Saruta/strace