logging: fix log_target_destroy(): properly close syslog

Change-Id: I122445e8ee842b5f807d21a272520648660e7e65
diff --git a/src/logging.c b/src/logging.c
index 78abc19..80ff72c 100644
--- a/src/logging.c
+++ b/src/logging.c
@@ -39,6 +39,11 @@
 #ifdef HAVE_STRINGS_H
 #include <strings.h>
 #endif
+
+#ifdef HAVE_SYSLOG_H
+#include <syslog.h>
+#endif
+
 #include <time.h>
 #include <sys/time.h>
 #include <errno.h>
@@ -964,6 +969,11 @@
 		fclose(target->tgt_file.out);
 		target->tgt_file.out = NULL;
 		break;
+#ifdef HAVE_SYSLOG_H
+	case LOG_TGT_TYPE_SYSLOG:
+		closelog();
+		break;
+#endif /* HAVE_SYSLOG_H */
 	default:
 		/* make GCC happy */
 		break;