$OpenBSD$

We need -std=gnu99 for !clang archs.
Fix install commands

Index: Makefile
--- Makefile.orig
+++ Makefile
@@ -1,7 +1,7 @@
 CC?=gcc
 PKG_CONFIG?=pkg-config
 
-CFLAGS?=-g -O2 -Wall
+CFLAGS+=-std=gnu99
 LDFLAGS?=
 
 PREFIX?=/usr/local
@@ -30,8 +30,8 @@ hsetroot: hsetroot.o
 hsr-outputs: hsr-outputs.o
 
 install: hsetroot hsr-outputs
-	install -st $(PREFIX)/bin/ hsetroot
-	install -st $(PREFIX)/bin/ hsr-outputs
+	install -sm 0755 -D hsetroot $(DESTDIR)$(PREFIX)/bin/
+	install -sm 0755 -D hsr-outputs $(DESTDIR)$(PREFIX)/bin/
 
 clean:
 	rm -f *.o hsetroot hsr-outputs