binutils: fix symlinks

For nativesdk, symlinks created by do_install contain ${SDKPATHNATIVE}.

This is a problem with SDKs that include nativesdk-binutils and nativesdk-gcc.
When extracting such an SDK dangling symlinks are created, because
relocate_sdk.py does not adjust symlinks. As a result gcc ends up calling the
host binutils.

Use the os.path.relpath function to obtain shorter relative paths, which do not
contain ${SDKPATHNATIVE}.

(From OE-Core rev: 3d6372aa2d9f752eac0e4943d1bde04f0f1924a0)

Signed-off-by: Achille Fouilleul <achille.fouilleul@gadz.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/binutils/binutils.inc

@@ -131,12 +131,12 @@ do_install () {
 	# We don't really need these, so we'll remove them...
 	rm -rf ${D}${libdir}/ldscripts
 
+	bindir_rel=${@os.path.relpath('${bindir}', '${prefix}/${TARGET_SYS}/bin')}
+
 	# Fix the /usr/${TARGET_SYS}/bin/* links
 	for l in ${D}${prefix}/${TARGET_SYS}/bin/*; do
 		rm -f $l
-		ln -sf `echo ${prefix}/${TARGET_SYS}/bin \
-			| tr -s / \
-			| sed -e 's,^/,,' -e 's,[^/]*,..,g'`${bindir}/${TARGET_PREFIX}`basename $l` $l
+		ln -sf $bindir_rel/${TARGET_PREFIX}`basename $l` $l
 	done
 
 	# Install the libiberty header