Renames log level enum values to not conflict with syslog

LOG_DEBUG conflicts with another enum definition in syslog.h,
which causes compilation errors when included. This renames
the enum values to be prefixed with LOGC instead of LOG to
avoid this

src/log.h

@@ -15,14 +15,14 @@
 
 typedef void (*log_LockFn)(void *udata, int lock);
 
-enum { LOG_TRACE, LOG_DEBUG, LOG_INFO, LOG_WARN, LOG_ERROR, LOG_FATAL };
-
-#define log_trace(...) log_log(LOG_TRACE, __FILE__, __LINE__, __VA_ARGS__)
-#define log_debug(...) log_log(LOG_DEBUG, __FILE__, __LINE__, __VA_ARGS__)
-#define log_info(...)  log_log(LOG_INFO,  __FILE__, __LINE__, __VA_ARGS__)
-#define log_warn(...)  log_log(LOG_WARN,  __FILE__, __LINE__, __VA_ARGS__)
-#define log_error(...) log_log(LOG_ERROR, __FILE__, __LINE__, __VA_ARGS__)
-#define log_fatal(...) log_log(LOG_FATAL, __FILE__, __LINE__, __VA_ARGS__)
+enum { LOGC_TRACE, LOGC_DEBUG, LOGC_INFO, LOGC_WARN, LOGC_ERROR, LOGC_FATAL };
+
+#define log_trace(...) log_log(LOGC_TRACE, __FILE__, __LINE__, __VA_ARGS__)
+#define log_debug(...) log_log(LOGC_DEBUG, __FILE__, __LINE__, __VA_ARGS__)
+#define log_info(...)  log_log(LOGC_INFO,  __FILE__, __LINE__, __VA_ARGS__)
+#define log_warn(...)  log_log(LOGC_WARN,  __FILE__, __LINE__, __VA_ARGS__)
+#define log_error(...) log_log(LOGC_ERROR, __FILE__, __LINE__, __VA_ARGS__)
+#define log_fatal(...) log_log(LOGC_FATAL, __FILE__, __LINE__, __VA_ARGS__)
 
 void log_set_udata(void *udata);
 void log_set_lock(log_LockFn fn);