build: Use portable compiler flag constructs in header compilation rule

diff --git a/Makefile b/Makefile
index 37faa76..5a7d591 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -46,7 +46,7 @@ COMPILE_S = $(call COMPILE,AS)
        $(COMPILE_S)
 
 %.ho: %.h
-       $(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ -x c $<
+       $(CC) $(CCFLAGS) -c $(CC_O) -x c $<
 
 %.ver: %.v
        $(Q)sed 's/$$MAJOR/$($(basename $(@F))_VERSION_MAJOR)/' $^ > $@