Change parameter types of s390's compat ipc syscall from unsigned long
to compat_ulong_t to enforce zero extension of these parameters.

This is not really a bug, since s390_ipc compat syscall is only a
wrapper to the generic compat_sys_ipc() syscall, which performs correct
zero and sign extension.

This was introduced with commit 56e41d3c ("merge compat sys_ipc
instances").
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>