get rid of ptrace_signal_deliver() arguments

the first one is equal to signal_pt_regs(), the second is never used
(and always NULL, while we are at it).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index b8e6dce..a89ff04 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -330,7 +330,7 @@
 #endif
 
 #ifndef ptrace_signal_deliver
-#define ptrace_signal_deliver(regs, cookie) do { } while (0)
+#define ptrace_signal_deliver() ((void)0)
 #endif
 
 /*