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

src/drivers/sf0x/sf0x.cpp

@@ -77,12 +77,6 @@
 
 /* Configuration Constants */
 
-/* oddly, ERROR is not defined for c++ */
-#ifdef ERROR
-# undef ERROR
-#endif
-static const int ERROR = -1;
-
 #ifndef CONFIG_SCHED_WORKQUEUE
 # error This requires CONFIG_SCHED_WORKQUEUE.
 #endif
@@ -756,12 +750,6 @@ SF0X::print_info()
 namespace sf0x
 {
 
-/* oddly, ERROR is not defined for c++ */
-#ifdef ERROR
-# undef ERROR
-#endif
-const int ERROR = -1;
-
 SF0X	*g_dev;
 
 void	start(const char *port);