ERROR macro: get rid of the many 'oddly, ERROR is not defined for c++', use PX4_ERROR

src/drivers/l3gd20/l3gd20.cpp

@@ -40,6 +40,7 @@
  */
 
 #include <px4_config.h>
+#include <px4_defines.h>
 
 #include <sys/types.h>
 #include <stdint.h>
@@ -74,12 +75,6 @@
 
 #define L3GD20_DEVICE_PATH "/dev/l3gd20"
 
-/* oddly, ERROR is not defined for c++ */
-#ifdef ERROR
-# undef ERROR
-#endif
-static const int ERROR = -1;
-
 /* Orientation on board */
 #define SENSOR_BOARD_ROTATION_000_DEG	0
 #define SENSOR_BOARD_ROTATION_090_DEG	1
@@ -476,7 +471,7 @@ L3GD20::~L3GD20()
 int
 L3GD20::init()
 {
-	int ret = ERROR;
+	int ret = PX4_ERROR;
 
 	/* do SPI init (and probe) first */
 	if (SPI::init() != OK) {