constify copy_siginfo_to_user{,32}()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/asm-generic/siginfo.h b/include/asm-generic/siginfo.h
index b685d3b..3d1a3af 100644
--- a/include/asm-generic/siginfo.h
+++ b/include/asm-generic/siginfo.h
@@ -32,6 +32,6 @@
 
 #endif
 
-extern int copy_siginfo_to_user(struct siginfo __user *to, struct siginfo *from);
+extern int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from);
 
 #endif