x86: ia32 ptrace vs -ENOSYS sysenter/syscall

The previous "x86_64 ia32 ptrace vs -ENOSYS" fix only covered
the int $0x80 system call entries.  This does the same fix
for the sysenter and syscall instruction paths.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>