powerpc/syscalls: switch rtas(2) to SYSCALL_DEFINE

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[mpe: Update sys_ni.c for s/ppc_rtas/sys_rtas/]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 9791364..3751a51 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -365,7 +365,7 @@ COND_SYSCALL(s390_pci_mmio_write);
 COND_SYSCALL_COMPAT(s390_ipc);
 
 /* powerpc */
-cond_syscall(ppc_rtas);
+COND_SYSCALL(rtas);
 COND_SYSCALL(spu_run);
 COND_SYSCALL(spu_create);
 COND_SYSCALL(subpage_prot);