$NetBSD$

Use BSD_INSTALL_* instead of mkdir and cp

--- man/Makefile.orig	2022-02-08 16:50:12.000000000 +0000
+++ man/Makefile
@@ -22,5 +22,5 @@ MANPAGES = $(addsuffix .1,\
 
 .PHONY: install
 install:
-	$(MKDIR) $(INSTALL_PROGRAMS_MAN_DIR)
-	$(INSTALL_DATA) $(MANPAGES) $(INSTALL_PROGRAMS_MAN_DIR)
+	$(BSD_INSTALL_MAN_DIR) $(INSTALL_PROGRAMS_MAN_DIR)
+	$(BSD_INSTALL_MAN) $(MANPAGES) $(INSTALL_PROGRAMS_MAN_DIR)
