engine: crashhandler: fully initialize struct sigaction

engine/common/crashhandler.c

@@ -440,7 +440,7 @@ static void Sys_Crash( int signal, siginfo_t *si, void *context)
 
 void Sys_SetupCrashHandler( void )
 {
-	struct sigaction act;
+	struct sigaction act = { 0 };
 	act.sa_sigaction = Sys_Crash;
 	act.sa_flags = SA_SIGINFO | SA_ONSTACK;
 	sigaction( SIGSEGV, &act, &oldFilter );