[POWERPC] Fix PPC32 SECCOMP, unexport do_syscall_trace_{enter,leave}

The secure_computing() call which automatically aborts a process if it
tries to execute a syscall it shouldn't is much more useful if we
actually do it _before_ the syscall, rather than afterwards. PPC64 got
this right, but the original incorrect behaviour inherited from arch/ppc
was preserved by ifdefs. Make it the same on PPC32 too.

Also, I see no need to export do_syscall_trace_{leave,enter} on ppc32 --
they were only exported because the old do_syscall_trace() (which they
replaced) used to be.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/kernel/ptrace.c

@@ -526,9 +526,7 @@ static void do_syscall_trace(void)
 
 void do_syscall_trace_enter(struct pt_regs *regs)
 {
-#ifdef CONFIG_PPC64
 	secure_computing(regs->gpr[0]);
-#endif
 
 	if (test_thread_flag(TIF_SYSCALL_TRACE)
 	    && (current->ptrace & PT_PTRACED))
@@ -548,10 +546,6 @@ void do_syscall_trace_enter(struct pt_regs *regs)
 
 void do_syscall_trace_leave(struct pt_regs *regs)
 {
-#ifdef CONFIG_PPC32
-	secure_computing(regs->gpr[0]);
-#endif
-
 	if (unlikely(current->audit_context))
 		audit_syscall_exit((regs->ccr&0x10000000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
 				   regs->result);
@@ -561,8 +555,3 @@ void do_syscall_trace_leave(struct pt_regs *regs)
 	    && (current->ptrace & PT_PTRACED))
 		do_syscall_trace();
 }
-
-#ifdef CONFIG_PPC32
-EXPORT_SYMBOL(do_syscall_trace_enter);
-EXPORT_SYMBOL(do_syscall_trace_leave);
-#endif