unix: move man pages in unix ports
diff --git a/unix/make/Makefile.fmt b/unix/make/Makefile.fmt
index 3a07840..2cf5f62 100644
--- a/unix/make/Makefile.fmt
+++ b/unix/make/Makefile.fmt
@@ -17,6 +17,7 @@
 	fmtfdflush.$O\
 	fmtlocale.$O\
 	fmtlock.$O\
+	fmtnull.$O\
 	fmtprint.$O\
 	fmtquote.$O\
 	fmtrune.$O\
@@ -51,9 +52,9 @@
 all: $(LIB)
 
 install: $(LIB)
-	test -d $(PREFIX)/man/man3 || mkdir -p $(PREFIX)/man/man3
-	install -m 0644 print.3 $(PREFIX)/man/man3/print.3
-	install -m 0644 fmtinstall.3 $(PREFIX)/man/man3/fmtinstall.3
+	test -d $(PREFIX)/share/man/man3 || mkdir -p $(PREFIX)/share/man/man3
+	install -m 0644 print.3 $(PREFIX)/share/man/man3/print.3
+	install -m 0644 fmtinstall.3 $(PREFIX)/share/man/man3/fmtinstall.3
 	mkdir -p $(PREFIX)/include
 	install -m 0644 fmt.h $(PREFIX)/include/fmt.h
 	mkdir -p $(PREFIX)/lib