switch the modules implementing the block structure to px4_poll such that in posix_sitl simulation the poll works as expected, blocks the module and doesn't overload the CPU

src/modules/segway/BlockSegwayController.cpp

@@ -3,7 +3,7 @@
 void BlockSegwayController::update()
 {
 	// wait for a sensor update, check for exit condition every 100 ms
-	if (poll(&_attPoll, 1, 100) < 0) { return; } // poll error
+	if (px4_poll(&_attPoll, 1, 100) < 0) { return; } // poll error
 
 	uint64_t newTimeStamp = hrt_absolute_time();
 	float dt = (newTimeStamp - _timeStamp) / 1.0e6f;

src/modules/segway/BlockSegwayController.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <px4_posix.h>
 #include <controllib/uorb/blocks.hpp>
 
 using namespace control;
@@ -22,7 +23,7 @@ private:
 	enum {CH_LEFT, CH_RIGHT};
 	BlockPI th2v;
 	BlockP q2v;
-	struct pollfd _attPoll;
+	px4_pollfd_struct_t _attPoll;
 	uint64_t _timeStamp;
 };