Nuttx: fixed include of systemlib/err.h

The new px4_debug.h included "err.h" instead of
"systemlib/err.h" for NuttX.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

src/platforms/px4_debug.h

@@ -39,6 +39,7 @@
 #pragma once
 
 #if defined(__PX4_LINUX) || defined(__PX4_QURT)
+
 #include <err.h>
 
 #define PX4_DBG(...)	
@@ -54,7 +55,8 @@
 #define PX4_ERR(...) 	ROS_WARN(__VA_ARGS__)
 
 #elif defined(__PX4_NUTTX)
-#include <err.h>
+
+#include <systemlib/err.h>
 
 #define PX4_DBG(...) 
 #define PX4_INFO(...)	warnx(__VA_ARGS__)