shadow: fix configure error with dash

A configure error occurs when /bin/sh -> dash:
  checking for is_selinux_enabled in -lselinux... yes
  checking for semanage_connect in -lsemanage... yes
  configure: 16322: test: yesyes: unexpected operator

Use "=" instead of "==" since dash doesn't support the latter.

(From OE-Core rev: a86da25d620aa9a2fd832ffe12816e7670b43633)

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/shadow/files/0001-configure.ac-fix-configure-error-with-dash.patch

@@ -0,0 +1,36 @@
+From 3c52a84ff8775590e7e9da9c0d4408c23494305e Mon Sep 17 00:00:00 2001
+From: Yi Zhao <yi.zhao@windriver.com>
+Date: Mon, 17 Jun 2019 15:36:34 +0800
+Subject: [PATCH] configure.ac: fix configure error with dash
+
+A configure error occurs when /bin/sh -> dash:
+  checking for is_selinux_enabled in -lselinux... yes
+  checking for semanage_connect in -lsemanage... yes
+  configure: 16322: test: yesyes: unexpected operator
+
+Use "=" instead of "==" since dash doesn't support this operator.
+
+Upstream-Status: Backport
+[https://github.com/shadow-maint/shadow/commit/3c52a84ff8775590e7e9da9c0d4408c23494305e]
+
+Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
+---
+ configure.ac | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/configure.ac b/configure.ac
+index 6762556..1907afb 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -500,7 +500,7 @@ if test "$with_selinux" != "no"; then
+ 			AC_MSG_ERROR([libsemanage not found])
+ 		fi
+ 
+-		if test "$selinux_lib$semanage_lib" == "yesyes" ; then
++		if test "$selinux_lib$semanage_lib" = "yesyes" ; then
+ 			AC_DEFINE(WITH_SELINUX, 1,
+ 			          [Build shadow with SELinux support])
+ 			LIBSELINUX="-lselinux"
+-- 
+2.7.4
+

meta/recipes-extended/shadow/shadow.inc

@@ -13,6 +13,7 @@ SRC_URI = "https://github.com/shadow-maint/shadow/releases/download/${PV}/${BP}.
            file://shadow-4.1.3-dots-in-usernames.patch \
            file://0001-Make-the-sp_lstchg-shadow-field-reproducible-re.-71.patch  \
            file://0002-gettime-Use-secure_getenv-over-getenv.patch \
+           file://0001-configure.ac-fix-configure-error-with-dash.patch \
            ${@bb.utils.contains('PACKAGECONFIG', 'pam', '${PAM_SRC_URI}', '', d)} \
            "