bmake: workaround for install-sh exec error.

srcpkgs/bmake/template

@@ -1,7 +1,7 @@
 # Template file for 'bmake'
 pkgname=bmake
 version=20150505
-revision=1
+revision=2
 create_wrksrc=yes
 short_desc="Portable version of the NetBSD make build tool"
 maintainer="Juan RP <xtraeme@voidlinux.eu>"
@@ -20,6 +20,7 @@ do_configure() {
 		../boot-strap op=build
 		cp linux*-*/bmake .
 	fi
+	sed -i '1s,:,#!/bin/sh,g' install-sh
 }
 do_build() {
 	mkdir -p bmake/bmake-build