[POWERPC] Kill sparse warnings in kprobes

Fix sparse warnings in powerpc kprobes:

  CHECK   arch/powerpc/kernel/kprobes.c
arch/powerpc/kernel/kprobes.c:277:6: warning: symbol 'kretprobe_trampoline_holder' was not declared. Should it be static?
arch/powerpc/kernel/kprobes.c:287:15: warning: symbol 'trampoline_probe_handler' was not declared. Should it be static?
arch/powerpc/kernel/kprobes.c:525:16: warning: symbol 'jprobe_return_end' was not declared. Should it be static?

Fix along the same lines as http://lkml.org/lkml/2008/2/13/642

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/kprobes.c

@@ -274,7 +274,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
  * 	- When the probed function returns, this probe
  * 		causes the handlers to fire
  */
-void kretprobe_trampoline_holder(void)
+static void __used kretprobe_trampoline_holder(void)
 {
 	asm volatile(".global kretprobe_trampoline\n"
 			"kretprobe_trampoline:\n"
@@ -284,7 +284,8 @@ void kretprobe_trampoline_holder(void)
 /*
  * Called when the probe at kretprobe trampoline is hit
  */
-int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+static int __kprobes trampoline_probe_handler(struct kprobe *p,
+						struct pt_regs *regs)
 {
 	struct kretprobe_instance *ri = NULL;
 	struct hlist_head *head, empty_rp;
@@ -517,12 +518,12 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
 	return 1;
 }
 
-void __kprobes jprobe_return(void)
+void __used __kprobes jprobe_return(void)
 {
 	asm volatile("trap" ::: "memory");
 }
 
-void __kprobes jprobe_return_end(void)
+static void __used __kprobes jprobe_return_end(void)
 {
 };