simulator and dumpfile fix minor resource leaks

 * Certain conditional branches returned before closing the file handler.

src/modules/simulator/simulator_mavlink.cpp

@@ -673,6 +673,7 @@ void Simulator::poll_for_MAVLink_messages()
 
 		if (bind(_fd, (struct sockaddr *)&_myaddr, sizeof(_myaddr)) < 0) {
 			PX4_ERR("bind for UDP port %i failed (%i)", _port, errno);
+			::close(_fd);
 			return;
 		}
 

src/systemcmds/dumpfile/dumpfile.c

@@ -99,6 +99,7 @@ dumpfile_main(int argc, char *argv[])
 
 	if (tcsetattr(out, TCSANOW, &tc) < 0) {
 		PX4_ERR("failed setting stdout attributes");
+		fclose(f);
 		return 1;
 	}