patch-Makefile

--- Makefile.orig	2015-04-24 23:13:47 UTC
+++ Makefile
@@ -18,9 +18,9 @@ LDLIBS =
 CFLAGS = -I$(PWD) -Wall -Wextra -Werror -g -O2
 LDLIBS =
 
-BINDIR = /usr/sbin
+BINDIR = ${PREFIX}/sbin
 MANSECT = 1m
-MANDIR = /usr/share/man/man$(MANSECT)
+MANDIR = ${PREFIX}/share/man/man$(MANSECT)
 DESTDIR = $(PWD)/proto
 
 PROGS = \