sys-libs/ncurses: CONFIG_SHELL back to EPREFIX/bin/bash

${BASH} (outside prefix) breaks cross-eprefix, having
  the resulting ncurses-config with non-prefix shebang.

  The original rationale to use ${BASH} was handled by
  the bootstrap script.

Reference: https://gitweb.gentoo.org/repo/proj/prefix.git/commit/?id=1307044f212d62

Package-Manager: portage-2.3.3

sys-libs/ncurses/ncurses-6.0-r1.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2016 Gentoo Foundation
+# Copyright 1999-2017 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 # $Id$
 
@@ -182,7 +182,7 @@ do_configure() {
 
 	# Force bash until upstream rebuilds the configure script with a newer
 	# version of autotools. #545532
-	CONFIG_SHELL=${BASH} \
+	CONFIG_SHELL=${EPREFIX}/bin/bash \
 	ECONF_SOURCE=${S} \
 	econf "${conf[@]}" "$@"
 }