GCC 4.6 warnings cleanup

sigaction.cc

Index: sigaction.cc
===================================================================
--- sigaction.cc	(revision 168)
+++ sigaction.cc	(working copy)
@@ -140,8 +140,10 @@
     return false;
   }
   SecureMem::sendSystemCall(*info, SecureMem::SEND_UNLOCKED,
-                           sigaction_req.signum, sigaction_req.action,
-                           sigaction_req.old_action, sigaction_req.sigsetsize);
+      sigaction_req.signum,
+      const_cast<SysCalls::kernel_sigaction*>(sigaction_req.action),
+      const_cast<SysCalls::kernel_sigaction*>(sigaction_req.old_action),
+      sigaction_req.sigsetsize);
   return true;
 }