Use syscall(SYS_gettid) instead of gettid()

Use syscall(SYS_gettid) instead of gettid(),
because gettid() can be undefined in older OSes.

Signed-off-by: Lukasz Dorau <[email protected]>

Author: ldorau

src/utils/utils_log.c

@@ -82,7 +82,7 @@ static void util_log_internal(util_log_level_t level, int perror,
     pid_t tid = (pid_t)tid64;
 #else
     pid_t pid = getpid();
-    pid_t tid = gettid();
+    pid_t tid = syscall(SYS_gettid);
 #endif
 
     char buffer[LOG_MAX];