Make sure we don't user std{err,in,out} if they don't exist.

This is required for target build in libosmocore

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/src/logging.c b/src/logging.c
index 5be4e58..b3b5cb6 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -294,14 +294,11 @@
 	target->categories[category].loglevel = level;
 }
 
-/* since C89/C99 says stderr is a macro, we can safely do this! */
-#ifdef stderr
 static void _file_output(struct log_target *target, const char *log)
 {
 	fprintf(target->tgt_file.out, "%s", log);
 	fflush(target->tgt_file.out);
 }
-#endif
 
 struct log_target *log_target_create(void)
 {
@@ -374,8 +371,12 @@
 	log_del_target(target);
 
 	if (target->output == &_file_output) {
+/* since C89/C99 says stderr is a macro, we can safely do this! */
+#ifdef stderr
 		/* don't close stderr */
-		if (target->tgt_file.out != stderr) {
+		if (target->tgt_file.out != stderr)
+#endif
+		{
 			fclose(target->tgt_file.out);
 			target->tgt_file.out = NULL;
 		}
diff --git a/src/process.c b/src/process.c
index ab4b37e..180efa5 100644
--- a/src/process.c
+++ b/src/process.c
@@ -63,9 +63,12 @@
 		return rc;
 
 	/* Redirect stdio to /dev/null */
+/* since C89/C99 says stderr is a macro, we can safely do this! */
+#ifdef stderr
 	freopen("/dev/null", "r", stdin);
 	freopen("/dev/null", "w", stdout);
 	freopen("/dev/null", "w", stderr);
+#endif
 
 	return 0;
 }