unify default ptrace_signal_deliver

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index e0ff468..7aefbae 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -329,6 +329,10 @@
 #define current_pt_regs() task_pt_regs(current)
 #endif
 
+#ifndef ptrace_signal_deliver
+#define ptrace_signal_deliver(regs, cookie) do { } while (0)
+#endif
+
 extern int task_current_syscall(struct task_struct *target, long *callno,
 				unsigned long args[6], unsigned int maxargs,
 				unsigned long *sp, unsigned long *pc);