fix spelling of systemdunitdir

Author: ka9q

service/Makefile

@@ -2,7 +2,7 @@
 # sub-make for ka9q-radio systemd .service files
 # Copyright 2026, Phil Karn, KA9Q
 
-systemunitdir ?= /etc/systemd/system
+systemdunitdir ?= /etc/systemd/system
 
 .PHONY: clean all install install-system
 
@@ -14,8 +14,8 @@ clean:
 
 # install as ordinary files for now, don't have dpkg autostart them
 install:
-	install -d 0755 $(DESTDIR)$(systemunitdir)
-	install *.service $(DESTDIR)$(systemunitdir)
+	install -d 0755 $(DESTDIR)$(systemdunitdir)
+	install *.service $(DESTDIR)$(systemdunitdir)
 
 install-system:
 	@true