pkgconf: revert changes to pkg-config-wrapper

To maintain the status quo, revert changes to pkgconf wrappers.
This helps to keep it compatible with freedesktop.org pkg-config.

(From OE-Core rev: 8ee8eb8a15e0e4a652df3fe77805d9cffa02ed22)

Signed-off-by: Maxin B. John <maxin.john@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/pkgconf/pkgconf/pkg-config-esdk.in

@@ -5,6 +5,7 @@
 if [ "pkg-config-native" = "`basename $0`" ] ; then
 	PKG_CONFIG_PATH="@PATH_NATIVE@"
 	PKG_CONFIG_LIBDIR="@LIBDIR_NATIVE@"
+	unset PKG_CONFIG_SYSROOT_DIR
 else
 	# in this case check if we are in the esdk
 	if [ "$OE_SKIP_SDK_CHECK" = "1" ] ; then
@@ -15,8 +16,9 @@ else
 		if ( echo $parentpid_info | grep -q check-lxdialog ) ; then
 			PKG_CONFIG_PATH="@PATH_NATIVE@"
 			PKG_CONFIG_LIBDIR="@LIBDIR_NATIVE@"
+			unset PKG_CONFIG_SYSROOT_DIR
 		fi
 	fi
 fi
 
-pkg-config "$@"
+pkg-config.real "$@"

meta/recipes-devtools/pkgconf/pkgconf/pkg-config-native.in

@@ -1,5 +1,6 @@
 #! /bin/sh
 
 PKG_CONFIG_PATH="@PATH_NATIVE@"
+unset PKG_CONFIG_SYSROOT_DIR
 
 pkg-config "$@"

meta/recipes-devtools/pkgconf/pkgconf/pkg-config-wrapper

@@ -4,4 +4,13 @@
 # Copyright (C) 2015 Christopher Larson <chris_larson@mentor.com>
 # License: MIT (see COPYING.MIT at the root of the repository for terms)
 
+for arg; do
+    case "$arg" in
+        --variable|--variable=*)
+            # pkg-config doesn't sysroot-prefix user variables
+            unset PKG_CONFIG_SYSROOT_DIR
+            ;;
+    esac
+done
+
 exec pkgconf "$@"