Use safe_syscall for waitpid, waitid and wait4 syscalls. Note that this
change allows us to implement support for waitid's fifth (rusage) argument
in future; for the moment we ignore it as we have done up til now.
Signed-off-by: NTimothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-18-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
[PMM: Adjust to new safe_syscall convention. Add fifth waitid syscall argument
 (which isn't present in the libc interface but is in the syscall ABI)]
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>