build: don't use '$<' in non-suffix rules

[Collin Funk]

On OpenBSD using the system's make, I see the following error:

    $ make
      GEN      src/speedlist.h
    Using $< in a non-suffix rule context is a GNUmake idiom (Makefile:29072)

Pushed the attach patch since it is a simple fix.

Collin


>From 72d483dab7cabcf4b18fbfa7429edc96967a4a50 Mon Sep 17 00:00:00 2001
Message-ID: <72d483dab7cabcf4b18fbfa7429edc96967a4a50.1753918934.git.collin.fu...@gmail.com>
From: Collin Funk <collin.fu...@gmail.com>
Date: Wed, 30 Jul 2025 16:33:24 -0700
Subject: [PATCH] build: don't use '$<' in non-suffix rules

* src/local.mk (src/speedlist.h): Use the file name instead of '$<'
which is not supported by OpenBSD make.
---
 src/local.mk | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/local.mk b/src/local.mk
index 50957a8cd..ef3b23249 100644
--- a/src/local.mk
+++ b/src/local.mk
@@ -717,7 +717,8 @@ src/speedlist.h: src/termios.c lib/config.h src/speedgen
 	$(AM_V_GEN)rm -f $@
 	$(AM_V_at)${MKDIR_P} src
 	$(AM_V_at)( for opt in $(getmacopts); do \
-			$(COMPILE) -E $$opt $< 2>&1 && break; \
+			$(COMPILE) -E $(srcdir)/src/termios.c src 2>&1 \
+                          && break; \
 		    done ) | $(SHELL) $(srcdir)/src/speedgen $@t
 	$(AM_V_at)chmod a-w $@t
 	$(AM_V_at)mv $@t $@
-- 
2.50.1