[S390] kretprobe_trampoline_holder() in wrong section.

kretprobe_trampoline_holder() is in kprobes section but used to
register a kprobe in arch_init_kprobes(). Hence register_kprobe()
and therefore arch_init_kprobes() will fail.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/kprobes.c

@@ -356,7 +356,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
  *	- When the probed function returns, this probe
  *		causes the handlers to fire
  */
-void __kprobes kretprobe_trampoline_holder(void)
+void kretprobe_trampoline_holder(void)
 {
 	asm volatile(".global kretprobe_trampoline\n"
 		     "kretprobe_trampoline: bcr 0,0\n");