useradd: Use modern join syntax

string.join() is deprecated syntax and doesn't work under python3
so use the modern sytax instead.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
buildstats: Drop spurious open() call

This file is already opened a few lines previously, so drop the duplicated
call.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
class/lib: Fix up various file access methods

There are various bits of cruft that have built up around our file accesses. This patch
cleans some of them up, specifically:

 * Remove pointless "from __builtin__ import file"
 * Use open(), not file()
 * Wrap file usage in a with container to ensure files are closed
 * Add missing .close() calls in some cases

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
imagetest-qemu: Fix indentation

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
eglibc/machine-sdk: Drop SDK_GLIBC_ADDONS

We no longer change GLIBC_ADDONS per target so we no longer need to special
case the SDK settings for it either.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>