Make use of $(STRIP) instead of hardcoded /usr/bin/strip

--- ./Makefile.in.orig	2013-01-13 14:43:54.667744706 +0100
+++ ./Makefile.in	2013-01-13 14:44:33.558744270 +0100
@@ -31,6 +31,7 @@
 
 # Compiler & tools to use
 CC = @CC@
+STRIP = @STRIP@
 FLEX = @FLEX@
 YACC = @YACC@
 NROFF = nroff -Tascii
@@ -486,8 +487,8 @@
 	  fi ; \
 	  cp $(srcdir)/INSTALL.binary $$tdir/INSTALL ; \
 	  sh ./config.status --file=Makefile.binary && cp Makefile.binary $$tdir/Makefile ; \
-	  strip $$tdir/sudo ; \
-	  strip $$tdir/visudo ; \
+	  $(STRIP) $$tdir/sudo ; \
+	  $(STRIP) $$tdir/visudo ; \
 	  cd tmp.$$ARCH && tar Ocf ../sudo-$(VERSION)-$$ARCH.tar sudo-$(VERSION) && cd .. ; \
 	  gzip -f --best sudo-$(VERSION)-$$ARCH.tar ; \
 	  rm -rf tmp.$$ARCH ; \
@@ -516,8 +517,8 @@
 	  printf '#!/sbin/sh\nrm -f /usr/local/man/man1m/sudoedit.1m\nln /usr/local/man/man1m/sudo.1m /usr/local/man/man1m/sudoedit.1m\n' > $$tdir/sudo-man.postinstall ; \
 	  printf '#!/sbin/sh\nif [ ! -s /etc/sudoers ]; then\n\techo installing /usr/local/doc/sudo/sudoers as /etc/sudoers\n\techo use /usr/local/sbin/visudo to configure sudo\n\tcp /usr/local/doc/sudo/sudoers /etc/sudoers\n\tchmod 440 /etc/sudoers\n\tchown root:root /etc/sudoers\nfi\n' > $$tdir/sudo-config.postinstall ; \
 	  chmod 755 $$tdir/sudo-exec.postinstall $$tdir/sudo-man.postinstall $$tdir/sudo-config.postinstall ; \
-	  strip $$tdir/sudo ; \
-	  strip $$tdir/visudo ; \
+	  $(STRIP) $$tdir/sudo ; \
+	  $(STRIP) $$tdir/visudo ; \
 	  cd $$tdir ; \
 	  swpackage -x target_type=tape -d ../sudo-$(VERSION).depot -s sudo.psf ; \
 	  cd .. ; \