x86_64: fix 2.6.18 regression - PTRACE_OLDSETOPTIONS should be accepted

["Paolo 'Blaisorblade' Giarrusso" <blaisorblade@yahoo.it>]

Also PTRACE_OLDSETOPTIONS should be accepted, as done by kernel/ptrace.c and
forced by binary compatibility. UML/32bit breaks because of this - since it is wise
enough to use PTRACE_OLDSETOPTIONS to be binary compatible with 2.4 host
kernels.

Until 2.6.17 (commit f0f2d6536e3515b5b1b7ae97dc8f176860c8c2ce) we had:

       default:
                return sys_ptrace(request, pid, addr, data);

Instead here we have:
        case PTRACE_GET_THREAD_AREA:
	case ...:
                return sys_ptrace(request, pid, addr, data);

        default:
                return -EINVAL;

This change was a style change - when a case is added, it must be explicitly
tested this way. In this case, not enough testing was done.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Index: linux-2.6.git/arch/x86_64/ia32/ptrace32.c
===================================================================
--- linux-2.6.git.orig/arch/x86_64/ia32/ptrace32.c
+++ linux-2.6.git/arch/x86_64/ia32/ptrace32.c
@@ -246,6 +246,7 @@ asmlinkage long sys32_ptrace(long reques
 	case PTRACE_SINGLESTEP:
 	case PTRACE_DETACH:
 	case PTRACE_SYSCALL:
+	case PTRACE_OLDSETOPTIONS:
 	case PTRACE_SETOPTIONS:
 	case PTRACE_SET_THREAD_AREA:
 	case PTRACE_GET_THREAD_AREA: