util: ifndef the etrace and trace macros

This macros are incredibly useful to use globally so let's ifdef them
out in case developers have them sitting around in global headers.

Part-of: <https://gitlab.freedesktop.org/libinput/libei/-/merge_requests/378>

src/util-macros.h

@@ -71,6 +71,7 @@
 	static int _once_per_##__func__ = 0; \
 	for (; _once_per_##__func__ == 0; _once_per_##__func__ = 1)
 
+#if !defined(trace) && !defined(etrace)
 #define trace(...) \
 	do { \
 		char buf_[1024]; \
@@ -84,3 +85,4 @@
 		snprintf(buf_, sizeof(buf_), __VA_ARGS__); \
 		fprintf(stderr, "\x1B[0;34m" "%s():%d - " "\x1B[0;31m" "%s" "\x1B[0m" "\n", __func__, __LINE__, buf_); \
 	} while (0)
+#endif