upstream: short circuit debug log processing early if we're not going

to log anything. From Kobe Housen

OpenBSD-Commit-ID: 2bcddd695872a1bef137cfff7823044dcded90ea

log.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: log.c,v 1.60 2021/09/16 15:11:19 djm Exp $ */
+/* $OpenBSD: log.c,v 1.61 2023/12/06 21:06:48 djm Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -469,6 +469,10 @@ sshlogv(const char *file, const char *func, int line, int showfunc,
 	const char *cp;
 	size_t i;
 
+	/* short circuit processing early if we're not going to log anything */
+	if (nlog_verbose == 0 && level > log_level)
+		return;
+
 	snprintf(tag, sizeof(tag), "%.48s:%.48s():%d (pid=%ld)",
 	    (cp = strrchr(file, '/')) == NULL ? file : cp + 1, func, line,
 	    (long)getpid());