powerpc: Remove old compile time disabled syscall tracing code

We have code to do syscall tracing which is disabled at compile time by
default. It's not been touched since the dawn of time (ie. v2.6.12).

There are now better ways to do syscall tracing, ie. using the
raw_syscall, or syscall tracepoints.

For the specific case of tracing syscalls at boot on a system that
doesn't get to userspace, you can boot with:

  trace_event=syscalls tp_printk=on

Which will trace syscalls from boot, and echo all output to the console.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/entry_32.S

@@ -33,9 +33,6 @@
 #include <asm/ftrace.h>
 #include <asm/ptrace.h>
 
-#undef SHOW_SYSCALLS
-#undef SHOW_SYSCALLS_TASK
-
 /*
  * MSR_KERNEL is > 0x10000 on 4xx/Book-E since it include MSR_CE.
  */
@@ -307,9 +304,6 @@ _GLOBAL(DoSyscall)
 	lwz	r11,_CCR(r1)	/* Clear SO bit in CR */
 	rlwinm	r11,r11,0,4,2
 	stw	r11,_CCR(r1)
-#ifdef SHOW_SYSCALLS
-	bl	do_show_syscall
-#endif /* SHOW_SYSCALLS */
 #ifdef CONFIG_TRACE_IRQFLAGS
 	/* Return from syscalls can (and generally will) hard enable
 	 * interrupts. You aren't supposed to call a syscall with
@@ -352,9 +346,6 @@ syscall_dotrace_cont:
 	blrl			/* Call handler */
 	.globl	ret_from_syscall
 ret_from_syscall:
-#ifdef SHOW_SYSCALLS
-	bl	do_show_syscall_exit
-#endif
 	mr	r6,r3
 	CURRENT_THREAD_INFO(r12, r1)
 	/* disable interrupts so current_thread_info()->flags can't change */
@@ -523,74 +514,6 @@ syscall_exit_work:
 	bl	do_syscall_trace_leave
 	b	ret_from_except_full
 
-#ifdef SHOW_SYSCALLS
-do_show_syscall:
-#ifdef SHOW_SYSCALLS_TASK
-	lis	r11,show_syscalls_task@ha
-	lwz	r11,show_syscalls_task@l(r11)
-	cmp	0,r2,r11
-	bnelr
-#endif
-	stw	r31,GPR31(r1)
-	mflr	r31
-	lis	r3,7f@ha
-	addi	r3,r3,7f@l
-	lwz	r4,GPR0(r1)
-	lwz	r5,GPR3(r1)
-	lwz	r6,GPR4(r1)
-	lwz	r7,GPR5(r1)
-	lwz	r8,GPR6(r1)
-	lwz	r9,GPR7(r1)
-	bl	printk
-	lis	r3,77f@ha
-	addi	r3,r3,77f@l
-	lwz	r4,GPR8(r1)
-	mr	r5,r2
-	bl	printk
-	lwz	r0,GPR0(r1)
-	lwz	r3,GPR3(r1)
-	lwz	r4,GPR4(r1)
-	lwz	r5,GPR5(r1)
-	lwz	r6,GPR6(r1)
-	lwz	r7,GPR7(r1)
-	lwz	r8,GPR8(r1)
-	mtlr	r31
-	lwz	r31,GPR31(r1)
-	blr
-
-do_show_syscall_exit:
-#ifdef SHOW_SYSCALLS_TASK
-	lis	r11,show_syscalls_task@ha
-	lwz	r11,show_syscalls_task@l(r11)
-	cmp	0,r2,r11
-	bnelr
-#endif
-	stw	r31,GPR31(r1)
-	mflr	r31
-	stw	r3,RESULT(r1)	/* Save result */
-	mr	r4,r3
-	lis	r3,79f@ha
-	addi	r3,r3,79f@l
-	bl	printk
-	lwz	r3,RESULT(r1)
-	mtlr	r31
-	lwz	r31,GPR31(r1)
-	blr
-
-7:	.string	"syscall %d(%x, %x, %x, %x, %x, "
-77:	.string	"%x), current=%p\n"
-79:	.string	" -> %x\n"
-	.align	2,0
-
-#ifdef SHOW_SYSCALLS_TASK
-	.data
-	.globl	show_syscalls_task
-show_syscalls_task:
-	.long	-1
-	.text
-#endif
-#endif /* SHOW_SYSCALLS */
-
 /*
  * The fork/clone functions need to copy the full register set into
  * the child process. Therefore we need to save all the nonvolatile